I’m guessing POR 15 might work as well, if only because it appears to close pinholes well enough to seal out fuel, according to a number of forum members on this other thread: Fuel resistant filament - #3 by RMB
Also, @JonRaymond has experience dipping ABS prints in acetone to get a smooth candy shell on his prints. Maybe he can comment as to their subsequent air-tightness, as perhaps that (or similar techniques) would work as well.
It sure would be a great help to print air-tight containers rather than to endlessly hunt for injection molded containers of the right dimensions.