I don't use the condom fill method. Takes too long.
I drip from the top, using a wooden toothpick to plug the center airhole. I drip and shake (like with a thermometer), drip and shake, until the polyfill appears like a slushy drink and stays that way.
I then remove the toothpick, replace it with a tank filling tool like the Slap-Yo-Moma, and lubricate it and the carto with some e-juice. I insert the carto halfway into the tank, fill the tank to 80% full of juice, and twist the carto the rest of the way into the tank.
Remove the tank tool, replace with a drip tip. Ready to vape. Takes 4-5 minutes.
A PBusardo Review - Slap Yo Mama Multi-Purpose Adapter - Big Daddy Vapor - YouTube