This is a physical bath bomb - not a mold.
Q: How do you put them together? Melt and pour soap?
Breaking the Mold YYC
A: You can use several different ways. On our group there are some videos that demonstrate how they go together. The two simplest ways is one to use a paintbrush dipped in water along the edge and seal them. Or to use cocoa butter along the edge and seal them.