Anyways, on to the point!
Take 1 cup of baking soda and pour it down the offending clogged sink. It won't all go down, because 1 cup is alot, but work with it. Then, pour 1 cup white vinegar. You'll feel like you're conducting a science experiment in your bathroom sink Now walk away for 20 minutes. Next, pour 4 cups of boiling water down the drain. That's it! Our drain is as good as new, environmentally friendly and free! :)