Most of them don't have origami instructions if they have instructions at all. I didn't find any beyond a few of the platonic solids.
The cut-and-stick nets aren't but the rest most certainly are! Look up "The Complete Book of Origami Polyhedra". I've made some of them myself: they use only square paper without tearing, cutting or sticking.
cloudhead · · focus · HN ↗
stronglikedan · · focus · HN ↗
rtkwe · · focus · HN ↗
speerer · · focus · HN ↗