Things that cause gurgling: leaky tank seal, drawing too hard, wattage too low, wicking not covering juice inlet holes, chain vaping ie.(overheating), insufficient wicking, coil set too high above airtube and leaving the device horizontal for extended periods. Check for these conditions. Gurgling leads to leaking so if you can get a handle on these you're home free.
Just spent a couple hours messing with the RBA wicks in both my units. No gurgles!
Wicking not covering juice inlet holes was definitely the culprit. Following the suggestion in the Engrish instructions that came with the RBA helped a bit, too.
Initially, when I first did these (described back on page 25), I had wicked the coils pretty long, primed them, and used a nail file to tuck them down tothe base bottom, then put in the RBA tube (the part with the juice inlet holes, there's four of them). I didn't take into consideration that the inlet holes, when the tube is screwed down tight, are actually up near the coil deck, so on one RBA, the wick was only covering three of the four holes.
This time around, after a lot of trial and error, I cut the wicks shorter, then followed step four from the instructions:
"Lift up the two sides of the organic cotton strip [wick], and then install the RBA tube. Next, use a tweezer to press the cotton into the two sides of the e-juice inlet."
So you're pulling up the wick ends from the coil, threading the two ends up into the tube, tube then gets screwed down, then tucking down the wick.
But: on one of my RBA bases (the one where I had only three holes covered due to my noob error), when the tube is screwed down, all four holes are exposed nicely around the deck. Totally obvious where to tuck, and I also used the pointy end of a thumbtack to help scootch things around so the air hole wasn't blocked and things were tidy around the coil. RBA cover went on, RBA went in the body, screwed down tight as possible, fired up, no gurgling.
On the other RBA base, when the tube is screwed down, two of the holes line up the with deck base, and there's virtually no room to tuck the wick in between the deck and the tube. That's where most of the trial and error went, was to get wicking down in there, or at least jammed around the coil screws and deck close enough. I suspect this has to do with the indexing of the tube threading / inlet hole drilling - can't imagine Joyetech is getting that particular about it. But this one was in the unit that gurgled a bit more than the other (but neither were seriously bad).
In any case, the end of a nail file and the thumbtack helped there too - I got enough wick down there and packed as best I could around the deck and coil screws, and both units were firing nicely right after reassembly - but as I write this, the one with the holes lining up with the deck is starting to gurgle a tiny bit at the beginning of the draw again.
Anyone having leaking or gurgling should be having a close look at how those juice inlet holes in the tube line up with the deck of the base itself. I tried one attempt at wrapping a super thin layer of the cotton that comes with the base around the sides of the deck, but the tolerances are so tight that the threads of the tube got hung up on it and wouldn't allow it to start threading.
Final note: that smaller slot in the RBA base around the air hole is a threaded sleeve that clamps the deck pieces down to the base body (I took the whole damn thing apart

) Both of mine weren't fully tight when I brought the bases home, and in fact had loosened up a bit after all the fiddling with the RBA. I'd recommend making sure that's tightened up after any coil / wicking action. (See the pic back on page 25, too.)
Blowing into the device to clear flooding can actually cause flooding by relieving too much of the air vacuum in the tank so I can't recommend it.
This is true, at least for the eGrip. Dennis at Cignot had mentioned doing something like this on his mod, when we were talking mod generalities - I tried it a few days after I had my RBAs in and the gurgling started to see if it would help, and it was messy.