I used the 32 oz. Drain Treatment and Cleaner in my bathroom sink and tub, these are by far the worst drains in my house. I followed the direction, shook the bottle, mixed the appropriate amount with water, let sit 15 minutes, then poured down the drains. I let it sit overnight. When I flushed it in the morning, it was Swish, clean drains, very impressed, and all with no harsh chemicals.
Dale via Homedepot.com BF PA November 23, 2015