Any Keglers on here?

[Omnimill]

I'm having some trouble with the thumb hole on my ball and the guy who runs the pro shop is on holiday. I've read that vent holes are quite commonly drilled to prevent suction problems. I think a vent may help as the hole size is otherwise ok. I have a 6x26 mill so I can do this myself. Has anyone on here tried it? I understand that the vent is normally drilled at 45° to the thumb hole.