Frequently Asked Plumbing Questions - This is a common plumbing troubleshooting question. Foul odors occur from a buildup of food debris within the disposal. To eliminate odors, place ice cubes and lemon peels or orange peels in the disposal, and run for 30 seconds. Next, squirt a little liquid dish detergent into the disposer while it is still running. Finally, run cold water for about 30 seconds to rinse all the debris away.