I'm going to email Mequiar and see if they have an MSDS for the Scratch X. I've just used it on 2 guitars, but not keen on silicone either.I used Meguiar’s Scratch out polish and found out later it contains silicone! I do not want silicone anywhere near any of my guitars. It wasn’t listed on the bottle, either.
I know Sonic has much more experience than me with the auto refinishing, and I get I his point about prep, but I also know that once I've "finished" a guitar, it doesn't mean it's going to stay that way forever.
I've been known to refinish a finished guitar once or twice...