I've been doing research about cleaning cartos and attys. I guess the basic question that I have is...
a) Can I use the same cleaning techniques shown on attys on cartos? and vice versa. Is it safe?
In answer to your question, it's not exactly the same, as cartos have filler material, as well as a center tube to draw vapor through. As a result, there are two more things to take care of:
1) The filler must be thoroughly cleaned and dried. Look up "taryn spin" here on ECF for a technique (centrifugal force) to get most moisture out of the filler immediately, which is important as you soak the filler a couple times to get clear liquid, whether using alcohol, water or both. It takes a couple good rinse/spins to get that filler clean.
Drying the filler requires dry heat to make it ready to accept liquid. Some people on ECF use an oven at low heat for a period of time. I set them threaded side down on top of the light bulbs in one of our bathrooms that has exposed bulbs. 30 minutes does the trick. As for safety, I believe between alcohol flushes and heat it's a clean outcome.
2) The center tube needs to be clear, so that you can see light through it looking from the mouthpiece side. If not, the draw gets very tight and refilling tends to hit the center and gurgle. Big reason for giving up on a carto early, in my opinion. If I can't see light after cleaning, before drying, I use a small paper clip straightened out to gently go from the threaded end through to the mouthpiece and open up the hole. Some people on ECF use a needle. I do it when they're damp so that they dry with the tube opening cleared.
Quite a bit more work than an atty! I do them in batches - my wife and I use them during work days and toss them in an ashtray, then I do a batch on the weekend and load them up for the next week. Takes about an hour to do a dozen.
I like reusing materials, including the ashtray! Only burning or excessive draw tightening are reasons to toss for me. Some have made it through 30 refills and still hold 25+drops and draw well!
I guess some people enjoy tinkering and some don't. You can definitely get them very clean and extend their life if you want to. I don't think it's a waste of time, as it's free time I'd probably spend on ECF! I just wish there was a pooling of regular cartos from those who don't care to clean them, so we could sanitize them and pass them on to those who can't afford much.