I got the clear cartomizers, now I don't have to wonder when it's time to re-fill. I can just look and see. It's helped a little bit to see the internal parts and know what is making it leak. lol, there is the tiny tube that comes to the top, try to avoid getting
juice in there. That helps. You can also blow it out if you miss. You learn over time to have a napkin around with you when you vape.
You can clean them if you want. however, if you keep them moist and not let them dry out, you can get away with not needing to clean for months. I bought my 5 clears a couple of months ago. I am still using them, and fully expect to be using them for several more months to come. They are definitely worth the money, and the longer you use them, the more money you are pocketing in the long run.