TST Orange RV Toilet Treatment Drop-Ins *15-PackThe Camco TST 12 oz. Orange Drop-ins are an effective and environmentally safe way to treat your RV's septic system. Simply drop one unit down the RV's toilet to stop odors and treat the water tank.Features:. Drop packet into your RV toilet to break down waste and tissue and treat both black and grey water tanks. Stops odors for up to 7 days. Fresh citrus scent. Environmentally friendly. Safe for septic tanks. Contains 12 packets