Ideally, we use washing soda in our drains once a week to keep them clear. Just pour 1/4 cup or so down the drain, and then flush with water. Washing soda is found in the laundry section of the supermarket.

OR

You can use baking soda instead by pouring 1 cup of baking soda down the drain, followed by three cups of boiling water. The boiling water will change the chemical composition of baking soda to become more alkaline like washing soda. If you already have a clog, try pouring 1 cup of washing soda (or baking soda) down the drain followed by three cups of boiling water. Repeat two or three times. If you still have a clog, try pouring down 1 cup of vinegar. Being an acid, the vinegar will neutralize the washing soda or baking soda and there will be some foaming and gurgling, but sometimes this agitation is all that is needed in the end to dislodge the grime.