This is a mold used for making Dunnies. If you want to easily remove the finished castings without damaging the mold, it is recommended to use flexible materials for casting.

I'm using Oogoo, and you can find its recipe here:
http://www.instructables.com/id/How-To-Make-Your-Own-Sugru-Substitute/
Oogoo's curing time is less than 10 minutes, so using 3D printing molds to quickly mass-produce products can be much more efficient :)。
Wish you a great time!