To clean any atty, I've tried not to dry burn them unless it's a last resort. Instead I will use plain PG or VG with 0 nicotine, drip enough in to flood the atty, heat the atty and blow it out. The gunk in an atty got there dissolved in PG or VG, and will re-dissolve in heated liquid. Less strain on the coils and a couple heat up and blow outs will clean them AND leave them moist and primed for use.