Open hair-clogged drains using salt It’s tough to keep hair and shampoo residues from collecting in the bathtub drain and clogging it. Dissolve the mess with 1 cup salt, 1 cup baking soda, and 1/2 cup white vinegar. Pour the mixture down the drain. After 10 minutes, follow up with a 1/2 gallon (2 liters) boiling water. Run your hot-water tap until the drain flows freely.