Have you thought about getting a ski with a metal top sheet? I find those hold really well for a mount. Usually when a ski says to use a 4,1 x 9 i use a 3,6 x 9 and let the screw thread the hole by hand tightening the screw. This way you get a nice hold and clean thread.
Quiver killers are an interesting concept, but i find it easier to spend the ~$90 on another set of griffons