Howdy,
This topic has been addressed a dozen or so times already with an older technology known as Carto's (Still used today). the set up and build is about the same as the Kanger heads. It would depend on a lot of things but mostly is the wicking material heat resistant, if it is then dry burning the coils will work just fine to clean them. If the material is not heat resistant then this poses a problem, ok so here is what I remember. Important note: Water is conductive
Using deionized water is a lot safer, it doesn't conduct electricity and will work just as effectively as tap water, the issue stands where what water will do to your wicking material. In cotton it causes it to bunch up and almost becomes unusable in a lot of cases, poly based materials seem to fare well for 1 or 2 cleanings before having an issue. Silica fares well after several cleanings and can be (to a point) dry burned without incident.
Vodka or Everclear will clean a coil if left overnight in it, since it is alcohol it will dry quickly when removed and should fare better on the cotton and poly material. Be sure not to use rubbing alcohol as it contains impurities that will not be good for you to vape. With both of the methods thus far you'll need to let the atomizer dry for a descent amount of time 3 days at minimum but longer is better.
The best way to go about it is to removing the wicking material and dry burn your coils, this removes any gunk built up on the coils and while your at it can replace the wicking material as it does wear out.
Dry burning is easy: put atomizer head on your mod, fire for 3-5 seconds 3 times, the coils should never ever glow white, your looking for a cherry red color and don't go beyond that. Anything further can damage the insulators and coils of your atomizer in truth.
Ultrasonic cleaners are not great, yah they work but more often then not I've found that they can damage the delicate circuits and coils in an atomizer head. I've lost a many cartomizers this way using an ultrasonic cleaner so personally I really don't fully trust them but if you want to experiment then won't say not to do it.
So there you have it, some base information..there is a lot more on ECF about cleaning cartomizers that would be a good read to start.