I had a clogged bunch of TP at the opening of our toilet after we had a bunch of family camp with us. I turned off water to the camper and when you stepped on the toilet lever, you could see it all down there. I did the needful and donned a glove and started pulling out as much as possible by hand.
After that, we took a hose in the door and used it full blast to break up the remainder of the clump. A clear elbow let us see what was coming out. It took 4 or 5 complete fillings and emptyings until it was finally cleared up.
I now give better directions when non-RV'ers are staying with us.