Amy Eberhardt got a reaction from Pugaboo in What Is The Difference Between Plaster Of Paris And Pottery Plaster?
You don't really have to pop the cured slab out of the box, Pug. The main reason for doing so is to prevent small bits from flaking off and getting into your work. If you clean up the slab in place, let it dry thoroughly, and there are no small bits around, you should be safe in just leaving it in the box. As dear old dad always said...."Work smarter, not harder"