I dont think so. I think I saw a grip made with something similar, a blowgun casted in some sort of glue, but I don´t remember who it was. But I agree as I haven´t seen a whole stock made out of it.
It was probably a grip made from polymorph. It's a plastic that you put in boiling water, then mold like clay. And there's a reason there aren't many hot glue stocks. It would perform terribly. Now an epoxy one would be fine, as long as it's not completely solid, for economical reasons. An epoxy stock with a foam core would be light weight, solid, and would get you bonus points for doing something extra.