Just in case other readers are confused on what I'm talking about, take this video for reference (its in Japanese but you can get the idea). pZero uses a 2-part clay silicone to make 2 part molds for some pieces, using not resin buy polyester putty to make multiple parts (through 5 minutes or so).

Liquid form silicone is slightly more difficult to use but is able to get details to the 'T' as it flows onto the pieces you need. Unfortunately, its a bit more tedious to do, messy, and needs some practice/experience to do well. Generally, the clay mold is less accurate and probably needs more sanding afterwards but much easier to pull off.