Yes, you can use silicone in a ComposiMold mold.
We frequently get asked if silicone can be used in ComposiMold, Here is a video that specifically shows how it is done from mixing the silicone to de-molding.
I looked in the toy box and found a bear that we have used for past projects. I decided to mold it and create a rubber bear! It’s so much fun to throw around and the dogs love it!