I used fastape. It's gray and made with actual Teflon. That said I've also tested branded white Teflon in gas without issue I just prefer the gray because it's 2-3x as thick and also has a "teletale" when it's working: it turns black when compressed. You can do a test fit and if it's still gray you didn't use enough.

__________________
2011 E70 • N55 (me)
2012 E70 • N63 (wife)