Welcome to the forum. The tp issue in the black tank can be avoided in a couple of ways. First fill the bowl like a residential toilet before using it. I use single ply scott tp. Flush when done and re-flush to be sure enough water is used to help it break down. To help keep the toilet bowl clean, place several pieces of tp on top of the water before using it. It will help keep the sides of the bowl clean by placing a barrier between the bowl and any solids in the bowl. When I dump the black tank before storage, I flush it out at least 3 times to be sure everything gets removed. A little bit of Dawn dish soap helps to keep the sides of the black tank clean and things from sticking to it(pour some into the toilet).
Paul
__________________
|