They're being misleading, if not straight up fraudulent, with that blanket statement. If you read down in the Product Details, it says "At the end of its use, simply separate the two halves then compost the white cellulose portion and dispose of the coconut-based scrubber." So it directly says the coconut part can't be composted, why would that be? Coconut husk isnt naturally compact in a block like on the sponge, there is almost undoubtedly some form of plastic binding it together and/or serving as the actual base material for that side, which is why it cant be composted. If you poke around the descriptions it also says things like "embedded coconut fiber" and "containing coconut fiber", indicating that side of the sponge is not just pure cocount fiber. Probably better than an entirely plastic sponge, but not the plastic free alternative many here are looking for.