crap what next?!
I use Permatex Ultra- Seal exclusively. I make sure the film of it is massaged into and sticks to the clean, oil free metal surface I am trying to prevent leaks from. I try to assemble the parts as soon as possible, while it is still "wet". Less is more around most parts.
I've had great results with this and it is much easier to take off than Gaskasinch.