I use the condom method, and whatever's leftover, or threatening to spill out, gets pulled out with a syringe and injected back into the bottle. My room looks like a chemist's lab, now!
If you insist on using the messy condom method (instead of just dripping directly into the filler, which is so much quicker, and then you'll know how many drops a empty carto takes when refilling and when filling new cartos), you can just pour the remaining juice in the condom back into the bottle. You don't need to use a syringe to put it back into the bottle. Pour and squeeze while pouring. Then clean up all the mess that comes with the condom method.
If anyone does decide to use the much quicker and less messy direct drip method, you can just blow lightly into the mouth end, and that will help the juice drain quicker into the filler, but letting the carto sit threaded end down for a few seconds will work fine, too.
For Boge 510 and KR808D-1 cartos:
When refilling, if you didn't vape the carto completely dry, it should take 12 to 18 drips by dripping directly into the filler, while holding the carto at a 45-degree angle. When filling new cartos, it should take 24 to 30 drips. If you overfill, just blow through the mouth end to remove the excess juice until it quits gurgling.
These are friendly tips that took me about three weeks to learn after I started vaping. I'm saving so much time now by not messing around with the condom method, taryn spins, overfilling, cleaning up messes, etc.
