There's no need to spend money on harsh, artificial drain cleaners when you can use something natural and likely already have in your kitchen: coffee grounds. Just like they absorb odors when used as a refrigerator deodorizer, coffee grounds can help freshen up your drains. Coffee grounds are abrasive, so they can help scrub away buildup in your drains. And since they're already wet, they can help break up grease and soap scum. To use coffee grounds to clean your drains:
Pour a pot of boiling water down the drain to loosen any debris.
Mix coffee grounds with equal parts baking soda and pour the mixture down the drain.
Let the mixture sit for a few minutes, then run hot water down the drain to flush it away.
For an extra-strength cleaning, mix the coffee grounds with salt, baking soda, and vinegar. Pour the mixture down the drain and let it sit for 30 minutes before running hot water down the drain.