black water tank -- I see toilet paper

A little water along with a chemical additive may help to keep anything left behind in a softened state and ready for the next camping trip. We tried the bag of ice trick once with little discernible benefit. They say to try this along with some water and Dawn dishwashing liquid. Can't hurt to try it and it will leave some water in the tank.

Some good reading here:

cleaning black tanks






Black tank cleaning