Hell yeah, I can get behind this. I can’t comment on the O-Cedar as I can’t get them here and information online is sparse, but the equivalent I get in Australia is made from cellulose and is biodegradable, apparently sadly not including the scourer (after some digging it’s coated in polyurethane).
There’s a store in my city called The Green Store that sells bio degradable kitchen stuff, and I accidentally found out they have an Australian website too:
I can’t see them online, but I usually get sponges that have loofah fibres attached to the sponge which I assume is cellulose. They also have coconut fibre in place of the loofah.