Superjay01,
I am soon to own a Huntsman but don't have one as of yet. My understanding is that any black powder rifle can use any of the substitutes for Goex such as Triple7 and Pyrodex. It's that way with every other muzzleloader I've ever seen in 23 years of shooting them. I'm going to try the Triple 7 in mine. Might even try some of that powder Jim Shockey markets under his name. The advertisements on it claim to just swab the bore with a patch and some hot water. I guess if Jim Shockey is willing to put his name on it, and by doing so his credibility, it should be pretty clean stuff.