Sew Clean. It is the best and most proven method of removing any build up of uric scale in black water systems. Formulated to target uric scale and clean sewage systems form toilet to tank, this proven solution can dissolve clogs causing plumbing to overflow and create nasty odors. Sew Clean builds upon the proven Barnacle Buster formula and takes it one step further. Special attention has been given to ensure that foam and bacteria are significantly reduced while flushing. Like all of TRAC's product, Sew Clean is non toxic, biodegradable and safe to use on all types of material commonly found in Black water systems.