You're going to need barn access for this one, but my girlfriend rents three paddocks for her Arabians named after Founding Fathers. Drill a hole in a board and feed your balls through the hole. Lay on your back on the horse's stall and then put the board across fitted into slots. Remain in this position until the horse steps on your balls at which point you will black out for several hours. You may wake up in Mexico or being buried alive in a coffin.