[header] How to clean drains [title] Treat your drain with white vinegar, baking soda, and hot water. [step] This can help eliminate odors caused by the buildup of bacteria, grease, and organic residue in your drain. It can also help clean out residue to prevent a future clog. 
Pour ½ of a cup (118 ml) of baking soda down your drain, followed by ½ a cup (118 ml) of white vinegar. Cover or plug the drain immediately and let the mixture sit for about 15 minutes.