Drain clogs don't usually happen overnight. They are caused by build-up over time inside the drain and pipes. Caustic cleaners put chemicals and toxins into the water supply and can be expensive. You can easily make an inexpensive natural drain cleaner that is much better on the environment and the pocket book using common pantry items. This cleaner can be used in bathroom and kitchen drains, as well as drains that have a garbage disposal.
Mix 1/4 cup salt with 1 cup baking soda and pour down the drain. Let it sit for for 3 to 6 hours.
Boil 1 cup vinegar with 1 cup water in a microwave-safe measuring cup or bowl.
Pour the boiling vinegar solution down the drain. The mixture will fizz and quite a bit of foam may come up the drain and into the sink. Boil more of the mixture and repeat 1 to 2 more times after the fizzing stops.
Turn on the faucet and flush the vinegar and baking soda out of the drain to avoid damage to the pipes from the acid solution.
Grind citrus peels in the garbage disposal to dispel odours. If there is standing water in the sink from the clog, sprinkle a cup of washing soda in the water and let it sit until it loosens the clog enough for the water to drain.
Contact a plumber if clogs persist to avoid long term damage to your pipes.