FLOWEASY Drain Opener dissolves ANY organic material (hair, grease, paper, rags, soap, sludge) to clear clogs in 15 minutes. It is safe to use on sinks, toilets, tubs, and shower drains. Will not harm septic tanks, metal, or PVC pipe. The power of FLOWEASY is in the proprietary formula that activates on contact with water. So, there is no need to remove water from the drain.