You can use citrus peels (oranges, lemons, limes, grapefruit) to help freshen up your sink. Put a handful of citrus peels into your garbage disposal, run the cold water and turn on the disposal. The citric acid will help deodorize your disposer and leave your kitchen smelling fresh. It’s especially a good idea to clean your garbage disposal before you leave your house for a few days. Having food, sludge and debris sitting in a moist garbage disposal that isn’t being used is a sure fire recipe for breeding odor-causing bacteria. Following these easy steps will help keep your sink smelling clean.