Joint compound in place of paper mache clay to sculpt a shell on a 3D model?

I am working on props for a local theatre production and trying to create/sculpt giant acorns. I’ve created a mold and done a layer of paper mache but to get the smooth and strong shell of the acorn, I was thinking of using a layer of joint compound. I’ve seen recipes for paper mache clay that use joint compound, but was wondering if anyone has used the substance on its own to build up layers on a 3D model and if they have any tips or tricks? Thanks!