Finally figured out a pretty good way to remove old gasket material

Fred Scigliano said
View attachment 1715320007 My gasket scraper the yellow works great on aluminum they make a green disc that is more abrasive for steel.

I use b12 chemtool in the spray can. From what the o.p. said , my way is a hell of a lot faster.
B12 chemtool, scraper/b12/maybe scrape again/ chemtool soaked rag/ rub it off