Bingo, the wire is encupsulated in solder vs being adheared as usual.
The fluid works too. But over time, as the pellet residue builds, mixing fluid in producess a slimy gunk that seems to slow the wicking process no matter what is used. I would stock up on a few bottles of pellet and stick with them.(testing a suppliers pellets before committing to a bunch as some crummy smoking aftermarket ones existed years ago)
Also, in the resivoir, there is a raised boss and hole for air. Note the height so you can guesstimate how much fluid it may hold. The wire element can run dry without damage if fluid is used.
Rewound ones can usually be found on de-bay. Remove a half wrap at a time then test to find the sweet spot.
