To eliminate foul odor from a kitchen sink, pour ¼ cup baking soda into the drain followed by ¼ cup white vinegar. Let the solution sit for 10 minutes, then rinse the drain with boiling water. The vinegar and baking soda not only deodorize the pipes but also break up and loosen debris. The boiling water helps push the newly loosened debris through the pipes.
In kitchen sinks that have garbage disposals, fresh citrus rinds are able to remove odors. Run these fresh citrus rinds through the garbage disposal with the tap water running. The citrus rinds deodorize any bad smell that may linger in the garbage disposal.
If bad smells are still noticeable, there is a chance that debris has become stuck in the trap beneath the sink; this is the U-shaped pipe. The job of the trap is to trap water in the pipe to prevent the smell of sewage from having a direct line into homes. Remove this pipe by loosening the retaining nut that holds the pipe in place. Use caution while removing this pipe because water may still be trapped inside. The pipe needs to be cleaned and replaced before running any water through the sink.