Use the"Monkey Snot" on the part you can remove the gasket with power tools. You never stick a valve cover gasket to the head, you always stick it to the cover and you can scrape it off and finish up with a wire wheel on a bench grinder. Don't you know that? Like a t-stat gasket, stick it to the housing not the intake.
Don't "I" know that? Yeah, I think after forty plus years I do. Who said anything about sticking anything to the head? Other than you? I always use a razor blade scraper to remove it. Usually it gets right under it and cuts it right off.