Homasote is made from recycled paper, like cellulose insulation, pressed together with a wax emulsion binder. The wax is used to provide moisture resistance. Ok, I googled it.
Was considering using homasote only, skipping the OSB layer, it is pretty stiff and would prob be ok with joists @ 16” oc, but it’s only 2 sheets so I’ll do the joists 24” oc with the OSB.