Harpic Drain Xpert Powder is a drain cleaning powder for use in blocked drains only. It melts grease and hair to unblock the drain pipe completely in 30 minutes. It does not damage the pipes, sinks or septic tanks. Can be used on all types of drains and pipes.Symptoms of drain cleaner poisoning include burns in mouth, difficulty breathing, drooling, and collapse. Swallowing this type of poison can have severe effects on many parts of the body. Damage to the esophagus and stomach continues to occur for several weeks after the sodium hydroxide was swallowed.