The Smooth on silicon worked perfect. If your trying this yourself use the Smooth-sil 940. That’s the food safe one. The problem was my shape has too small details and too much relief for an effective mold. So I am going to try again soon with a new design.
I think that if you took a file or sandpaper to the sides so they were not vertical you would get better results, no matter what you are casting and especially when the material is not like water vertical sides are a bad thing both for getting the material in or out.
If you had a way to have a vacuum chamber to put them in that would help as well both for the silicon and the chocolate. a bit of modeling clay pre silicon would help as well so not to change the design at the top.
A very cool idea!