Between the wife and I, we have 10 Kanger BDC tanks (Pro III Minis, EVOD II, EVOD Glass) and, for what its worth, I never had much luck cleaning the coils. I tried dry burning, alcohol soaking, etc. but they never seemed to work as well or taste as good as new.
I bought some 30ga Kanthal, and surgical cotton, and I now rebuild them as single coils. 8 wraps on a 1/16" drill bit gets me a single coil at 1.8 ohm. I run a small, tightish wick through the coil and top off with a loose "flavor wick" to fill in the dual coil slot. They seem to work as well as the factory coils, and cost all of about $0.10 to make and only take about 3 minutes to make.
Now we change coils on a whim. If we get a dry hit, think its wicking poorly, or change to a radically different flavor, we change the coil without a second thought and throw the old one in a bag. Once a week or so, I sit down and re-wrap the dirty ones collected in the bag. Its a one, maybe two beer job at most.