Are you talking about Gunk "Fuel Injection Air Intake Cleaner"?
http://www.gunk.com/prodinfo/M4712_6.PDF
If so, you'll have no problem with the gasket. (Actually, I can't imagine anything advertised for throttle body cleaning would damage the gasket.)
I'm just wondering why you had the engine running when you did this. The directions state that the engine should be off and cool. I don't really think it would hurt anything, just won't be as effective (no time to soak in).
