The most common complaint about garbage disposals is bad odors. There are a number of products on the market for deodorizing garbage disposals, but the best way to solve this problem is with citrus rinds. After you have squeezed the juice out of an orange or a lemon, cut up the rind into a few large pieces and grind them up in your garbage disposal. Citric acid is a powerful deodorizer. Use cold water. Hot water will flush away the citric acid.