if you were to swallow a lead weight attached to a long string you wait until you shit it out again, pull it inbetween your legs and make a loop and a knot around the tip of your dick.

take the other end thats coming from your mouth and pull if firmly down to one of your toes and attach it with the same kind of loop and knot as before.

you can now fuck yourself up the ass everytime you take a step.