I have a black tank about 2/3 full of toilet paper from this past weekend when I should have told people not to put it in the toilet. Today, I flushed the tank, poked at it with a stick through the toilet to try to break it up, flushed some more, etc. I can now use it because some of it did flush out. (I have one of those flushing systems for black water tanks that I hook a hose to on the outside of my vehicle while leaving the black water valve open and the sewer hose stuck into the dump station. It sprays the inside of the tank pretty well.)
I know I need to not let it dry out, but it was 100% full and I had to get the level down a bit so there was enough space for me to use it today and tonight. I added about a cup of the blue liquid "Full timers" because it did say on the bottle it would help dissolve TP. I also put in as much water as I dared and will add more tomorrow morning before I leave.
I am driving about 250 miles tomorrow, so I am hoping the motion will stir things up a bit and help the process. I figure when I get to my new campground tomorrow night, I will dump and use my sanitary system flush again.
Any suggestions on what else I could add? (And yes, next time, I will warn my guests more strongly and ask them to toss paper in the wastebasket.)