Yes, I've seen your automatic whip - didn't know if you still had it - glad you do.  I would revise my thinking about using it just on the ass cheeks with wide straps.  I would also have a thin strap available to aim at his tied up balls and/or his pucker hole.  Before it gets stuffed with anything, it needs to be warmed up a bit.  And I like cbr998's idea of tying the tit clamps to his toes to get pulled and yanked.  I would add the tied up balls, too, to his toes.  