What club did he use? I think that I'd go with a choke-down 5. Six-iron might do it, but that's one that you do not want to be short on...
As for other weaponry, a .22 works good, but it really needs to be a head shot. The reason I like a .22 is the noise aspect. And, it is quite sporty to try for a kill with a .22. Use a 3x or 4x scope, and if you can, get a semi-auto for faster shooting.
A 20 ga., loaded with 6's, is really much more efficient. With a 20 double-barrel, you have nothing to worry about. If anything is moving after one barrel (likely just wind moving a dead tail), the second barrel will be the end.
Also, very important; a pre-dug hole is very, very important when you need to take care of a skunk infestation. You don't want to start digging if you already have a dead skunk that required three shots with a .22 and which ran 50 yards into some bushes before croaking. Very bad.
Hope this was helpful.