works. Baking soda is idiotic.
A principal cause of drain clogs is mineral build-up from the water itself, rust from older iron pipes, and black mold (really, yes, black mold in your drains). Vinegar will dissolve those. (As well as your granite or marble countertop if you're not careful.)
DO NOT USE BAKING SODA NO MATTER WHAT SOMEBODY MORE STUPID THAN YOU SAID. Throwing baking soda down the drain along with the vinegar will defeat the process and actually add to the clog. The vinegar will be working to dissolve the baking soda, the baking soda will be working to neutralize the vinegar, and the clog will be eating popcorn and watching the two fight it out. Once the baking soda has neutralized the vinegar, it will reform itself into a solid and become assimilated into the clog. The idea of combining baking soda and vinegar was likely conceived by idiots who think that the foaming bubbles will work out the clog. For that matter, never throw baking soda down your drains, ever. It's powdered rock, for crying out loud. Get past fifth-grade science fair volcanoes, morons, and think about how things work.
So here's how you do it. Get a gallon of cheap white distilled vinegar from the supermarket. Pour it down your drain until it backs up to the top of your drain. Start boiling a teakettle full of water. You should see, after a time, the vinegar drain out. Pour the boiling water down the drain. If you have been eating all your vegetables and saying your prayers every night, you should see the water drain fast with a whoosh and/or gurgle. Clog gone.
To be safe, pour the remaining vinegar down the drain. Keep pouring even though it's draining away. Vinegar is cheap. Pour another teakettle of boiling water down the drain. Get the idea? You're hunting down the broken up survivors of the clog.
As a final step, wash the vinegar (and any clog remnants) thoroughly out of your pipes by letting your faucets run for a couple of minutes. You don't want it sitting there -- it will corrode the pipes.
WARNING: If you do not know that boiling water and vinegar should be handled carefully because they can hurt you or your family members, you have no business being alone on the internet. Find an "assisted living" home that does not have a minimum IQ requirement.