Grab some baking soda and sprinkle it in and on the drain. If it just sits on top of the drain, that's okay.
2. Pour white vinegar down the drain. Add as much vinegar as you can
without overflowing the clogged drain. You will immediately be able
to see the baking soda and vinegar start to go to work. Together,
they will form bubbling carbon dioxide, which will naturally clear
away any build-up.
3. Plug the drain with a stopper.
4. Allow it to sit for 10 minutes.
5. Remove the plug and run very hot water through the cleared drain