TL;DR
A foot file collects a dense pack of dead skin in its teeth, and if it goes into a drawer damp, that pack becomes a fungal breeding ground. Brush the file out under running water after every use, wash it with soap, and dry it completely before it is stored. Metal rasps can be disinfected with rubbing alcohol. Never share one with anyone.
The three kinds of foot file
The right cleaning method depends on which one you own.
Metal rasps. A stainless steel head with rows of raised teeth or a perforated grater surface. Durable, washable, and the only type that truly tolerates disinfecting. Some have replaceable heads.
Abrasive-surface files. A plastic or wooden body with a bonded mineral grit surface, similar to sandpaper. The grit clogs and eventually wears smooth. Water is tolerated but the bonding and the backing both degrade over time.
Ceramic and glass files. A fired abrasive surface, nonporous and easy to rinse. These clean up better than any other type and last a long time if not dropped.
Electric callus removers are their own category: the roller head detaches, and only the head should meet water. Never rinse the motor housing.
Pumice stones sit alongside all of these and are covered separately in how to clean a pumice stone.
How do you clean a foot file?
Tap out the loose skin, then hold the file under warm running water and brush the surface with a stiff brush, working across the teeth or grit until nothing more comes out. Wash it with a drop of dish soap, rinse thoroughly, and dry it completely before storing it in a ventilated place.
The routine after every use
1. Tap and brush off the loose skin first. Do this over a bin or a sink you can rinse, dry, before water is involved. Wet skin debris turns to paste and packs into the teeth.
2. Rinse under warm running water. Hold the file at an angle so water runs across the teeth rather than into them.
3. Scrub with a stiff brush. An old toothbrush or a nail brush. Work in the direction the teeth run. This is the step that actually clears a rasp.
4. Wash with a drop of dish soap. It cuts the skin oil that binds debris together.
5. Rinse until clear.
6. Dry completely. Towel first, then air. A metal file that goes into a drawer damp will rust at the base of the teeth, and any file that stays damp becomes a fungal risk.
7. Store it ventilated. Not sealed in a plastic bag or a zipped pouch while damp.
The drying rule runs through everything in a bathroom, as our guide to cleaning the personal items you use every day explains.
Disinfecting a metal rasp
Cleaning removes debris. Disinfecting reduces organisms, and it only works on a surface that has already been cleaned.
For stainless steel rasps, the practical home method is rubbing alcohol. Wash and dry the file first, then wipe or submerge the head in seventy percent isopropyl alcohol and let it stay wet for the contact time listed on the bottle before air drying. Alcohol needs the surface to stay wet to work; a quick wipe that flashes dry does very little.
Boiling water is an option for an all-metal file with no plastic or wooden handle. Five minutes, removed with tongs, dried completely and immediately to prevent rust.
Do not use bleach on a metal foot file. Chloride bleach pits stainless steel, and residue on a tool that abrades skin is not worth it.
Never mix cleaning products. Bleach with vinegar or any acid releases chlorine gas, bleach with ammonia releases chloramine gas, and both cause real injuries. One product, rinse, done.
Abrasive-surface files and wooden-handled files should not be soaked or boiled. Wash the surface, dry it, and replace it more often instead. That is the same tradeoff described in how to clean a nail file or replace it.
Why should you never share a foot file?
Foot files remove skin, and skin carries fungus and virus. Athlete's foot, fungal nail infections, and plantar warts all spread on shared tools, and household disinfecting is not reliable enough to make sharing safe. Everyone in a home should have their own file, cleaned and dried after every use.
When to replace a foot file
Abrasive-surface files wear smooth. Once the grit no longer bites, replace it. Most last a few months with regular use.
Metal rasps last for years, but replace one that has rusted at the base of the teeth, has bent or broken teeth, or has developed a rough burr that could cut skin. Files with replaceable heads should get a new head rather than a new tool.
Ceramic and glass files last a long time. Replace one that is chipped or cracked, since a chipped edge cuts.
Replace any file after a fungal infection rather than trying to disinfect it back into service, and replace one that has been dropped somewhere unclean.
The safety rules that outrank the cleaning
Callus is protective tissue. Removing too much makes skin thinner, more sensitive, and more prone to cracking, which is exactly the opposite of what people want.
Use a foot file on damp, softened skin after a shower or a soak. Work gently, in one direction, and stop while some callus remains. Aggressive filing on dry skin causes tearing.
Never use a foot file on cracked, bleeding, irritated, or infected skin, and never on a wart or a corn without medical advice. Abrading either can spread it.
Anyone with diabetes, peripheral neuropathy, or circulation problems should not use a foot file, a pumice stone, or any abrasive foot tool without talking to a doctor or a podiatrist. Reduced sensation means an injury goes unnoticed, and a small wound on a foot with poor circulation can become serious quickly.
Never use a callus shaver with a blade. Those are not safe for home use and a podiatrist has better tools and training.
Persistent thick callus, painful corns, cracked heels that will not heal, or any sign of infection belong with a podiatrist rather than a harder file.
Source: American Podiatric Medical Association consumer guidance on foot care
Keeping the whole kit clean
Foot files usually live in a drawer with nail clippers, scissors, and files, and cross-contamination between them is real.
Clean each tool after use rather than at the end of a session. Store them dry, and in a ventilated case rather than a sealed bag.
Clippers have their own hinge and debris problem, covered in how to clean nail clippers that are gunked up.
Wash your hands before and after, and clean the surface you worked on. Skin dust travels further than people expect.
FAQ
How do you clean a metal foot rasp?
Tap out the loose skin dry, rinse under warm running water, and scrub across the teeth with a stiff brush and a drop of dish soap until nothing more comes out. Rinse, dry completely to prevent rust, and wipe with rubbing alcohol if you want to disinfect it as well.
Can you disinfect a foot file with alcohol?
Yes, for metal, glass, and ceramic files. Clean the file first, since disinfectant does not work through debris, then keep the surface wet with seventy percent isopropyl alcohol for the contact time on the bottle and let it air dry. Do not soak abrasive-surface or wooden-handled files.
Can you share a foot file with family?
No. Foot files remove skin, and athlete's foot, fungal nail infections, and plantar warts all spread through shared tools. Home cleaning is not reliable enough to make sharing safe. Everyone should have their own file, cleaned after each use and stored dry and separately.
How often should you replace a foot file?
Abrasive-surface files last a few months and should be replaced once the grit no longer bites. Metal rasps last years, but replace one that has rusted, bent teeth, or a rough burr. Replace any file after a fungal infection rather than attempting to disinfect it back into use.
Can you boil a foot file?
Only an all-metal one with no plastic or wooden parts. Five minutes in boiling water, removed with tongs and dried immediately to prevent rust. Abrasive-surface files, wooden handles, and electric callus remover bodies must never be boiled or submerged.
Should you use a foot file on wet or dry skin?
On damp, softened skin after a shower or a soak. Filing dry callus tears the skin and removes material unevenly. Work gently in one direction and stop while some callus remains, since callus is protective and removing too much leaves skin thin and prone to cracking.
Personal tools are quick. The bathroom around them is not. If you would rather hand that off, get a quote or read more about house cleaning services.