Here's how I clean mine.
To get the juice out of the carto, I use an air nozzle with a compressor. Hold the battery end of the carto with a paper towel covering it, and about 10 seconds of 130psi air thru it will get most of the juice out. Then I take a single strand of CAT5 wire, and gently run it thru the air hole a few times, to loosen up the crap. Then I use a syringe and needle, and run about 100ml of denatured alcohol thru the carto. Fill your syringe up, and just blast that carto a few times. Hit it again with the air nozzle, to get the DNA out of it, 30 seconds or so will work, because DNA evaporates quickly. Then re-open the airhole again, if necessary, with the CAT5 wire. Let it sit for a few minutes, refill, and vape. Now, I don't inhale the 1st 10 or so hits after cleaning like that, because there is usually a tiny amount of DNA residue left in there. After that tho, it's fine.
If you do try this, don't try to blow anything out of the carto by putting the air nozzle at the battery end. I did that once, and 130psi shot the entire coil/diaper/polyfill across the room....