I've
vaping on the blue foam/Highping cork. Cut the foam to just slightly larger than the cart opening, put 1.8ml juice into the cart, squeezed the foam with tweezers to place it into the opening, then droppered another 10-12 drops on top of the foam slowly, allowing the foam to soak it up.
It's vaping. The jury is still out. Early indications that leakage might be a problem.
EDIT: Ugggg, just got juice in my mouth.

My attempt might be a flop. Or maybe I overfilled.
Looking for recommendations from you pros out there.
Post Edit: My atomizer was flooded, I blew it out. For now, doing better.
Later:
Well, this just isn't working. I hope someone else comes up with something.
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Even later still: Ok, ok, ok. The problem was partly the fact that my battery was nearly drained. Shortly after my "later" entry, I got the flashing LED and went to a fully charged battery.
Thanks for the input in post #3
sanfordf. I don't think I'll give up on this yet. Next time, I will cut back on the amount of juice loaded though. And, I like both the Mega cartos and carts, but am looking forward to a better selection of juice selection on both of them in the prefilled versions. I haven't refilled a carto yet. I'll try that this weekend.