Good old methylene chloride. Aka Dichloromethane, it is used by Permatex in its gasket remover spray. Don't get it on paint or clear-coated surfaces, as it is also a primary ingredient in paint stripper. If you are lucky, a local paint store will still have some of the aerosol paint remover which contains the stuff. An amazing solvent (heavier than water, evaporates almost instantly, boiling point of 112ºF), it penetrates and softens the gasket. Less scraping. Less chance of dinging the gasket surface.
Apparently, there are health concerns regarding the stuff, so it is getting harder and harder to find. A little drizzle of it plasticwelds fairing cracks instantly. It's so dangerous that they use it to...
...decaffeinate green coffee beans.
I finally figured out why I like Ducatis: With their exhaust note and dry clutch, they sound almost like a Guzzi!