Karl got me the white board and we are looking to get another bigger one for him and everyone else to use. Such a great tool!
I wore a belt the first time I ever did stones (was in a contest) and the stone pinched the belt on my skin so bad that my belly was black for a month. A few guys wear a belt when they do stones but almost all of the top guys don't. It really isn't hard on your back and IS a natural motion believe it or not. It is a lot of abs, hamstrings, lats, biceps, and explosive power...very little lower back.
Stones can be made fairly easily and cheaply and it is some of the most fun you can have with your clothes on.