What can wet toilet paper not do.
My youngest lived in the same room for 18 years until he moved out for college. The walls were originally white. After he moved, I took down all the posters, pictures, glow in the dark stars etc and was going to repaint. He had used wet toilet paper over the years to patch holes from knives, balls, golf clubs, whatever. If the repair was noticeable, he put a poster or something on the wall. When he came home for a visit I showed him what a can of spackle and drywall tools looked like. He is pretty good at that now.