I shucked for about a year at a busy seafood spot here in Maine(which frankly have some of the best oysters in the world, sorry southies... I do like a nice Kumamoto tho...). If you know what you're doing, you can use a flathead screwdriver, but I prefer the 'western' style spear tip. Tried the French 'spade' shape. And IMO the suck! And the Japanese style ones scare the crap out of me. I've shucked literally- thousands of oysters. The western style is the safest, and IMO the best. A chain mail glove is a good investment for sure, but proper placement of a dish towel(wrapped around the entire oyster, with your non dominant hand cradling), and a tender probing technique, will yield great dividends. But literally- you can use anything that will fit into the hinge, as long as you control the amount of force you apply. I've used butter knives, screwdrivers, pocketknives, spoons...
Btw- it's very difficult to cut the lower tendon cleanly with the French style, without mangling said oyster. Japanese style look as though they might be a little more effective, but based on how many sushi restaurants I've frequented where they don't perform this procedure... Not to say that all sushi joints use J-style oyster knives...