Hi All, N00b to the forum. Been vaping for two + months. Have about 15 carto's from the various kits I've tried. I find that after about three days with one carto they get clogged so bad that even a good 5 miniutes in boiling water doesn't clean them out. I've taken a few apart to have a look and they seem to get a burnt 'caking' on the element. I've seen some video's that they feed a higher voltage through the carto and burn the baked stuff off but that is risky. I know, I've fried a few carto's attempting this. Is there a better way to clean them than just water without getting a chemically reside afterwards?