Drano Liquid Drain Cleaner 32 oz, Pack of 12Safe for garbage disposals, bathroom, kitchen and other drains like laundry sinks. Drano liquid drain cleaner starts working to unclog your drain on contact. After 15 to 30 minutes, clogs are substantially minimized or dissolved. A final blast of hot water flushes away what's left of the clog. Wont cause septic tank problems Contains an ingredient to protect pipes from corrosion Can leave in drains overnight Contains no phosphate, a potential cause