The trick is to allow enough non-compressible fluid into the cavity to disrupt the bullet/jacket. Will silicone allow for that under various conditions, hard to tell. It appears to me that the "insert" that Hornady uses is slightly more rigid than your average caulk. I would probably try to replicate the durometer of what they use as closely as possible, since I'm sure that they went thru many test cycles to determine what works best.
I can guarantee you it won’t be easy to turn it into jack shit. The digital part may be new, but we’ve done the backed by a physical item thing, and it’ll be a mess. There’s an inherent issue with pulling enough of a thing of value out of the global economy in as volume large enough to represent the global economy.