A thick gel that clings to pipes and drains, this solution repels unsanitary drain flies with citronella. It’s biodegradable, too, as well as non-toxic and non-caustic. And its ingredients qualify for the 25(b) exemption in EPA Pesticide Regulations. Ideal for grease traps, garbage disposals, dumpsters, sewer lines, drain lines, down pipes, and septic tanks. 1 qt. 12/Case.