In the history sheets for my car I noticed that it had "valve cover gasket replaced" - which I figure is the process above. A few years back I went to install the X-51 baffle in my oil sump, and this is what I found:
Once I started doing UOA with blackstone I have had high silicone readings, I think because there are still a few remnants of this floating around somewhere. Not the recommended sealant (which is black) and way too much. I wish I had taken more pictures, in addition to what was here there were a few larger ones that were just sitting in the bottom of the pan... Don't use too much sealant!