The first step to a healthy garbage disposal is to clean out around the rubber splash guard (please be sure to cut off power to your disposal before doing so). Food products can often become lodged in this area if it has not been rinsed well after running the garbage disposal. You should run water down your garbage disposal drain for 40 – 60 seconds before shutting off the disposal! A sponge or a bottle brush will usually scrub around your slash guard well enough to knock off any remaining food particles! If your rubber splash guard is removable you can lift it out to clean it as well.
Now, when it comes to finally getting rid of that foul smell, you have a few great choices! Vinegar and baking soda: Sprinkle ordinary baking soda into your garbage disposal, enough to just cover the inside of the drain. Next pour about a 1/2 cup of vinegar into the disposal. Do not run the disposal! Let the mixture sit for an hour then run cold water into your drain while running the disposal. After the smell of vinegar evaporates you will notice the absence of the initial foul food smell.
Citrus and Borax: Pick a citrus of your choice (lemon, orange, etc) and slice about half of it into small sections. Running the water and the disposal, drop the fruit into the disposal one piece at a time. Remember to continue running the water and disposal for 40 – 60 seconds! After the 1/2 fruit has been sent down the disposal you can disinfect the drain area by flushing it with a 1/4 cup of Borax every few weeks. Now that your garbage disposal problem is fixed, you can enjoy the other half of your fruit! Bleach detergent: Plug your drain and fill the tub with water and a small amount of bleach detergent. Using rubber dish gloves, mix around the water and bleach, then pull the stopper out of your drain. This will flush out your disposal with water and disinfectant, washing away the odors! In addition to these home remedies you can also find deodorizing agents at your local supermarket.