Hair,
Well you could do that, might work a couple of times but I think what you will end up doing is ruining a case or two. Wad punches are actually cheap, a couple of suppliers have them for 15.00 or 20.00 dollars or so. And at your local hardwhare store they have Arbhor punches that you can modify with a file to cut a punch any size you want. Then it's just a matter of finding matereal to punch from. If Veggioe wads are what you are after the local auto parts have gasket matereal that is a veggie wad source. Poly wads are pretty easy to come by as well. This is one instance where you will much better off cutting your own. Get a punch and hammer away.
Gunny