Instead of purchasing an expensive product to clean the garbage disposal, try out some remedies. Given below is a list of some easy solutions that you can try at home:

1. Citric Acid
Lemon, orange, or any other citric juice plays a major role in getting rid of the garbage smell. It ultimately leads to a very fresh and pleasant smell. The acidic nature of citrus fruits helps to remove all the grease and bacteria which are basically causing the stinky smell. You can cut the fruit into two halves and then squeeze them into the garbage disposal. This is one of the simplest and easiest yet most effective ways to remove the smell instantly. So, do try it and see if it works for you or not because I have tried it multiple times, and proved to be really effective.
Source: https://smellproofguide.com/how-to-get-rid-of-the-garbage-disposal-smell/