Loving all the tech and pics approach, in here. I did a full-batch boil/vodka/oven cleaning a few weeks ago. I'm not sure how well they turned out, but my current carto is certainly acceptable.
There is one very important cleaning tip I figured out today, though. Pay closer attention to the BATTS! Those two teeny-tiny air intake holes are much more important than I had previously thought. I had previously just been giving them a good wipe with tissue once in a while, enough to see I was getting the more exterior gunk out. But, my newly cleaned cartos had been acting very hit-or-miss.
Some were DOA, refusing to vape. Some tasted burned, and I foolishly tried to vape them clear, destroying the silicon seal. A few performed well and lasted me the average week I would put a new carto through.
But, today, I killed a batt. I don't know how or why, but the rare carto will develop a deterioration in the seal. It will vape like an empty, but refill like it's full. This is because the juice just leaks out through the seal, and the carto never really fills up. I was stuck at work, and didn't have any other cartos on me until I was able to run home for lunch. So I was dumping juice in this thing way too often, but still vaping a non-stop empty taste.
Then BAM, no vapor. I was getting air-flow and batt lighting, but no heat going through at all. Once I was able to try other cartos on the batt, I knew I'd killed it. Once I took a closer look at the frustrating carto, I knew it had flooded my batt through the damaged seal.
I quickly took out my thankfully still-working batt and gave it a very thorough look over. Gunk I hadn't noticed before, and wasn't being reached by my simple wipings, had clogged those tiny little holes. I got a pin and started scraping away!
And holy cow, it's definitely made a difference. The liquid I had been puffing on all day without a care has suddenly thrown me back into nic-highs. The draw is obviously clearer, and the vapor is back on high. And though I had been convinced my batts were drawing to their end, dying much quicker than they used to, this partially-charged, newly-cleaned batt has lasted me longer than it had been when it was fully charged and dirty.
On the bright side, it's given me a definite reason to place a new order. I'm super excited to get my XL Green in.
In the end, dirty batts aside, after the standard boil-cleaning, the cartos that still worked, worked well enough for not being new. Hopefully cleaning the batt will have resolved the carto-killing issues.