Not sure if this helps or if this is already part of your coil maintenance, but when I dry burn my coil, I also take the end of a paperclip to the coil itself and scrape the residue off the coil. Just dry burning takes a lot longer and sometimes you don't get all of the gunk off. I'm still trying to figure out why my coils are lasting so long.
I was not doing that.
Will try. Thanks a lot!