TL;DR
Clear the drip channel and grease tray after every session -- an indoor grill that smokes is almost always burning fat from a full tray, not from the food. If your plates detach, wash them by hand while they are cool. If they do not, steam the ridges soft under a damp paper towel for five minutes and wipe. The base holding the element is never submerged.
Removable or fixed decides everything
Look at the hinge and the plate edges for release buttons or clips. Removable plates go to the sink. Fixed plates never do, because the heating element and wiring sit directly beneath them.
Getting this wrong is how an indoor grill dies -- water in a fixed housing corrodes contacts and can create a shock hazard the next time the unit is plugged in.
This is the same first question you ask about a panini press and its ridged grill plates, and it is one of the central rules in the small appliance cleaning guide.
How do you clean an indoor grill?
Unplug it and let it cool to warm, then release and remove the plates if your model allows and wash them by hand in warm soapy water with a nylon brush. If the plates are fixed, lay a damp paper towel over the warm ridges for five minutes so steam softens the residue, then wipe with a soft cloth. Empty and wash the drip tray, and wipe the housing with a soapy cloth.
Warm is the right temperature to work at. Cold residue turns into a varnish; hot plates are dangerous and flash-dry the cloth.
Work along the ridges, not across them, so a brush reaches the bottom of each groove.
The drip channel is where the smoke comes from
Indoor grills funnel fat down a channel into a removable tray. When the tray fills, fat backs up into the channel and eventually onto the heating area, where it burns -- and that is the smoke people blame on "smokeless" marketing.
Empty the tray after every session. Pour cooled fat into a container and put it in the trash, never down a drain, where it hardens and builds a clog.
Wash the tray in hot soapy water, and run a cloth-wrapped fingertip or a skewer down the channel itself. The channel is easy to overlook because the tray looks like the whole system. Grease behaves identically on an electric griddle and its grease drip tray.
Water-tray models
Some indoor grills use a shallow water tray beneath the plates to catch drips and reduce smoke. That water needs emptying and the tray needs washing after every use.
Old grease sitting in water goes rancid quickly and smells the moment the grill heats. It is the single most common source of an off odor on these models.
Fill the tray to the marked line each time you cook. A dry tray on a model designed for water lets fat hit the hot surface directly, which produces exactly the smoke the tray exists to prevent.
What ruins the plates
Steel wool, scouring pads, abrasive powders, oven cleaner, and metal utensils all cut nonstick and ceramic coatings. Once a plate is scored, food catches in the scratch and the grill becomes harder to clean on every future use.
Chloride bleach pits stainless housings and does not belong on a cooking surface. Never combine bleach with vinegar, a descaler, ammonia, or rubbing alcohol in one container, because those combinations release toxic gases.
Let plates cool before they touch water. A hot plate dropped into a cold sink can warp, and a warped plate never seats flat again.
For bird owners: overheated nonstick coatings can release fumes that are dangerous to pet birds, which have unusually sensitive respiratory systems. Never run an empty grill on maximum to burn residue off, and keep birds out of the kitchen while it is hot.
Source: U.S. Consumer Product Safety Commission guidance on small appliance care
The lid, the hinge, and the vent
Lids on contact grills collect the same residue as the lower plate and get skipped because they are less visible. Clean the underside of the lid every time.
The hinge collects a crust of drips that eventually keeps the lid from closing evenly, which shows up as food that cooks on one side only. A dry toothbrush and a skewer clear it, and no water goes in there.
Open-grate grills often have a vented hood or a fan on the smokeless models. Wipe the hood, and clear the fan intake with a dry brush -- a greasy fan grille is another cause of smoke that people misdiagnose.
Washing removable plates properly
Let them cool first, then wash in warm soapy water with a soft sponge or a nylon brush. Rinse and dry completely with a towel before reseating them, since a damp plate clipped back into a housing traps moisture against the element.
Many plates are labeled dishwasher safe. Handwashing still extends coating life, because dishwasher detergent is far more aggressive than dish soap and the drying cycle runs hot.
Store the grill only when everything is bone dry, closed and upright if the manual allows.
A rhythm that works
After every session: empty and wash the drip or water tray, clear the channel, and clean the plates.
Weekly with regular use: wipe the hinge, the hood, the fan intake, and the exterior.
Monthly: check the cord, the latch, and the plate coating for wear.
Cleaning removes soil and rancid fat so food tastes right and the grill stops smoking. It does not sanitize a kitchen or prevent illness. High-heat cooking spreads grease well beyond the appliance -- the same problem an electric wok without ruining its coating creates -- and if the whole room needs a reset, house cleaning services can take it.
FAQ
Why does my indoor grill smoke so much?
A full drip tray or a blocked drip channel is the most common cause, because backed-up fat reaches the hot surface and burns. Empty the tray and clear the channel after every session. On water-tray models, a dry tray produces the same symptom, so fill it to the marked line.
Can indoor grill plates go in the dishwasher?
Only if the plates detach and the manual says they are dishwasher safe. Fixed-plate grills and the housing never go in a dishwasher or a sink. Even for dishwasher-safe plates, handwashing with dish soap is gentler and keeps the nonstick coating working for considerably longer.
How do you clean a fixed-plate indoor grill?
Unplug it, let it cool to warm, and lay a damp paper towel across the plates for five minutes so steam softens the residue. Wipe with a soft cloth or nylon brush along the ridges, then go over it with a cloth wrung out in plain water. Nothing is submerged.
Can you use a wire brush on an indoor grill?
No. A wire brush cuts nonstick and ceramic coatings, and a scored plate grabs food permanently. Use a nylon brush, a soft cloth, or a silicone spatula, and let steam do the loosening. Wire brushes belong on bare cast iron outdoor grates, not on coated indoor plates.
How often should you clean an indoor grill drip tray?
After every session. Fat left in a tray goes rancid, smokes on the next use, and can back up into the drip channel. On water-tray models, empty the water each time too, since grease sitting in standing water is the fastest route to an off smell.
How do you get burnt on food off grill plates?
Soften rather than scrape. Lay a damp paper towel over warm plates for five minutes, or soak removable plates in warm soapy water for twenty minutes, then work them with a nylon brush. Repeat instead of increasing pressure, since abrasives and metal tools permanently damage the coating.
Indoor grilling is one of the greasiest things a kitchen does, and most of that grease ends up somewhere other than the grill. Every home is different, so the real number depends on size, condition, and what you want covered. Get a quote and we will walk you through it.