Carbon is very inert. You cant dissolve it or hardly react with it. Might be possible to break it off, but likely not effective as chance of damaging the wire. The focus should be on where it comes from and what else is produced during the reactions/breakdowns that we are inhaling.
uuhm.
Well.
We have had great success removing it from atomizers with cola soaks...Many posters have reported that atomizers which were useless are restored to 100% after a good RC bath.
The phosphoric acid / carbonic acid combination makes one hell of a carbon remover.
We also know that isopropanol is solvent to carbon as a nonpolar.
We KNOW where it comes from, in my opinion. I think I've demonstrated that e-liquids form carbon deposits when they are vaporized. Those deposits seem to be worsened by VG.
So...I don't think the issue, anymore, is why. I think the issue is how to control the issue.
Also, as far as what is produced during the vaporization process, this has been tested. I don't know where the link is but it's been done and, so far, there's been no reports of anything known to be harmful.