So I'm having a little better luck again with my Mega. I got a new style 1.5 ohm head and stuffed cotton in the air chamber and so far no leaks or gurgling. The new heads have a single long hole on each side versus 2 small hole on each side.
Any way you could walk through this process, taking some detailed pics along the way? Being a noob and the owner of a brand new Mega dual coil who has already experienced some of the same issues you encountered, I'd be REALLY interested in seeing what you've done.