Regular or RV toilet paper?

Back in the 80's when my family had a class C motorhome, my father jokingly told my older sister not to use more than two squares of toilet paper or it would clog the black tank. Years later, my sister admitted to not realizing it was a joke, and never used more than two squares!

Use cheap single-ply septic safe toilet paper, and feel free to use more than two squares.