Sculpting and modeling are very different. Sculpting you make blocks and carve, modeling is more like clay where you can shape it, ply it, mold it, and then have it set. Like a salt-dough.
We use a lot of modeling chocolate throughout the year. It's just chocolate + a ratio of corn syrup. As it cools it hardens and is pliable, over a few days it gets harder and harder almost like curing the more water that is freed the more rigid it becomes. If you have mass left over you can always reheat it later and knead it back into use.
