If you pop the closed oysters onto a hot grill they will pop open after a couple of minutes without shucking. You'll have a par cooked oyster but I bet you could open, let cool then top with your topping and reheat.
Traeger lil Tex, 2 Weber 22.5", UDS
Mop, Sauce & Two Smoking Barrels BBQ Team
They call me "Dave"
Veteran Noobian Warlord