Gather your supplies.
Sprinkle small amount Baking Soda over Drain to prevent clogging or clean out odor. If clogged, dump at least 1/2 cup right on drain through the backed up water.
Add enough vinegar to clear out baking soda. The two make a reaction that foams and clears out any debris in it's way.
When you can no longer hear the foaming going down your Drain, rinse with Hot Water. Ta-Da! Fresh, Clear, Odor Free Drain!