These are the best I've ever found. They're not silicone impregnated but rather have VCI made into them. Vapor phase corrosion inhibitors have been around a long time. I was using rolled up lengths of Brownell's VPI paper for bore protection way back in the 80s.
This is the long, one piece sock.
https://www.beretta.com/en-us/product/beretta-gun-sock-vci-SFOU65001 And, this is the two piece for use when the gun is broken down. I use the two piece ones in my LOM cases.
https://www.beretta.com/en-us/product/beretta-gun-sock-vci-2-pcs-takedown-SFOU65010
