Bones
As a mainstream in the garbage disposal process which includes grinding of bones, it is still not applicable to use the unit to extremely grind hard items such as rack of ribs. Chicken wings or fish bones are no issues but the harder bones, can easily dull the blade of the garbage disposal and cause incomplete grinding which can lead also to clogging.

Nuts
If you have been dumping peanuts on your garbage disposals, you need to stop it right away. Garbage disposal is more like an appliance-sized version of a peanut grinder which can mash peanuts into a sticky, thick paste and could emit a foul smell in the long run. Just a perfect form of clog you would like to avoid.

Onion Skins
It should not be a problem unless you put it down into the garbage disposal only its thin membrane that lies below the dry, outermost layer of the onion. But if you put all the waste from the onion including its skin, roots, and leaves, these can still pass through and miss blades and can block the drain like a cargo net in place.
Eggshells
The idea of dropping eggshells into the garbage disposal is normal and though these can somehow sharpen the blades of the garbage disposal and the shell itself doesn’t do any damage, the thin membrane on the inside of the shell can be loosened up and lodges in the drain.

Cleaning Chemicals
Dishwashing soaps and other detergents are fine to use and won’t affect the garbage disposal. However, the use of drain busters and industrial-grade cleaners can put extreme wear on the garbage disposal.
Paint
Latex or oil paint should never go down into your garbage disposal. It can stay on the side of the disposal or in pipes where it will harden into an intractable clog unless it is heavily diluted. The problem is, many DIYers usually do not dilute their paints before putting them into their garbage disposals. However, we don’t suggest dumping your excess paint into the garbage disposal because these belong to special or hazardous waste. 
Seashells
Seafood hard shells are a common garbage disposal problem since they cannot be grounded properly. Shrimp shells can be ground though but pose a possibility of getting stuck in the drain and cause clogging. If you suspect that the blades of the unit are dull and can’t disintegrate even shells of seafood, use the tips on how to clean garbage disposal with ice. 
It is very common to put down these listed materials on our sink thinking that our garbage disposal device will do the job for us. Unfortunately, some people have gotten used to dumping these into their sink which punishes the unit and can eventually show bad signs which will call for repair. But as we have mentioned, you must know the tricks either on how to clean a garbage disposal with baking soda which can eliminate odor and for the bad smell, learning how to clean a garbage disposal with vinegar is essential.