I asked Vicki at Cignot.com, authorized distributor for the Joye 510 cartomizers. She said "Those are filled by Joye... they only have PG." One option would be to
buy the empty Joye cartomizers and fill them with VG
juice yourself, which is not difficult. You can just hold them with the battery tip upright and place a drop on the little hole in the metal tip, and it will wick into the carto. About as fast as it disappears, you can have the next drop ready, and before you know it you have put 20 drops into it and you're ready to go! If the drop sits there and doesn't go into the carto, just give a few gentle taps on the table, still holding the metal end up and tapping the mouth end. It may have a bubble or something keeping it from flowing. It really goes very quickly and easily. Be sure to wipe off all
juice from the carto before attaching the battery, and if it leaks a little bit at the connection point, take the battery off and dry it again, just to protect the battery. HTH