Once it's burnt it's hard to clean, you can pull the head, rinse it with as hot a water as you can stand..soak in alcohol, rinse, squeeze in your hand in a paper towel, then do a dry burn to cook all the extra residue out
DO NOT USE RUBBING ALCOHOL! I have found that using grain alcohol (Everclear) works best

Here is what I do ...
1. Rinse coils under hot water for about 30 seconds, wrap in a paper towel to dry off excess moisture, repeat 2 or 3 times.
2. Place coils in a shot glass.
3. Cover coils with Everclear and allow to soak for at least 12 hours (longer if really gunked up)
4. Remove coils from shot glass, wrap in paper towel to remove excess moisture and allow to dry for about 4 hours. If you can't wait, then dry burn them for about 20 seconds, wait 60 seconds and repeat. Do this as many times as necessary to dry them out.
I have found I can get anywhere from 2-4 cleanings out of each coil before it needs to be replaced.
YMMV, hope this helps.