grammasharon:
I looked up several sites but settled on this one. The only thing I did different was that I let it set for a couple of hours before flushing the drain with hot water. The reason I did that was because several sites said to let it sit for a few hours before flushing with hot (almost boiling) water & one even said to let it sit overnight. This method will not clear drains of things like hair, etc. but it will take care of mineral & grease build up on the inside of the pipe.
https://www.ehow.com/how_7803686_use...tic-lines.html