I was messing with a flanged
tank carto and found that the tube portion of the carto was press-fit to the
threaded base.
(THIS IS THE PART I DON'T RECOMMEND)
While the carto was attached to my PV (for leverage) I twisted the tube with a pair of pliers and it came apart from the threaded base. Inside I found the poly-fil was a single sheet wrapped around the coil assembly, and the coil itself had an insulating thingy of it's own that looked like it worked as a wick.
This was a Smoktech flanged, pre-punched carto. Of course if you're dripping
juice into one of those, you're gonna leak haha.