Wondering how to clean a garbage disposal that smells bad? Remove any clogs before cleaning with soapy water, ice cubes, and coarse salt. Follow these steps to clean a smelly garbage disposal and learn how to prevent odor from returning: 1. Safely unclog your garbage disposal using tongs. 2. Soak garbage disposal in soapy water. 3. Clean garbage disposal using salt and ice cubes. 4. Use baking soda and vinegar to deodorize the disposal and prevent future odors.