a lot will also depend on just how rotten the spalted wood actually is. there is a HUGE difference between some decomposition staining and ink lines on an otherwise structurally sound piece of wood and what is sometimes sold on eBay as stunningly spalted (but not structurally sound) wood
the latter will require some kind of stabilizing - whether it be an epoxy enfusion, edge binding, or other
all spalting is not equal
all the best,
R