This product works well, the nice part is it does not smell like a perfume making the RV smell like a portable toilet at the fair. This product has been in my holding tanks just sitting there for about a month now. To see how this work I pulled one of the stoppers out of the drain that was pretty nasty. After 2 days there are signs of the residual nasty stuff being eaten away.
MrZ2 via Homedepot.com Boca Raton, FL December 3, 2015