Posted this in the 'burning carts
thread' to keep the info easily found (and still need to update with the KR cart timed breakdown/pics) in the future, either way, but as this is directly relevant to the G300 and greencigs:
To recap on the carts:
The Greencig carts are a bit $, but...they don't burn, and are refillable via several methods. Here's one disassembled again. The O-ring comes from the mouthpiece end, and the piece in middle is a 'regular cart,' like the 510 or other cart, with normal poly fill inside.
This is what the cart innards look like with the mouthpiece and cart removed (yes, sorry, it's blurry..but note the shiny coil):
This is what the atty coil and 'mystery hair' wick look like, up close. Note this is after multiple days of use with refills via both methods, via drip from battery end, and cart removal/refill. No burning, although obviously the atty's getting a bit...crusty

Have not tried to rinse, clean, dry burn this cart, may try later as an 'in-between' before refills vis disassembly and refill..