Op u gotta understand, corking is just throwing some backflip into a horozontal spin. A cork 3 is even amount of spin and backflip, so it just rotates around a diagonal axis.
a double cork 3 would look like a double backflip with some separate axis wobbling going on.
so yeah, a dub 3 is possible but its not going to look fuck all like a cork.
i think mike wilson did some sort of trick like this at vail big air in like 03 or 04.
I dont know what the name of the trick was tho.