Back in the 60's when the Buick V-6 was first built, silicone was used for "boob" enhancement, not in engines?
When I get a Buick engine and it is smeared with silicone, I know some unexperienced person has been in there making a mess.
My worst nightmare is when a "genius" seals an oil pan or timing cover to the block with the Right Stuff, and it takes hours to remove.