I hit my cartos hard and long and my cartos are, for the most part, fine.
I also rarely clean them out completely but I'm not sharing mine. I only fully clean them when there is a bad flavor "stuck" in it. I try blowing it all out and refill before I clean when the bad taste "just appeared" and isn't too strong of a bad flavor. This usually works. This vaping and refilling is time consuming enough!!! Cleaning and drying I try to avoid. I haven't gotten sick yet ... ha ha??? I top off when the carto is about 1/2full usually....almost all of the time. As soon as the flavor or vapor isn't PERFECT for a couple of drags...I drip and Taryin Spin and move on to vaping the same carto.....if I want. If I'm not going to vape that same carto right away I may just drip and sit upright (batt end down)...for a while...at least 30 mins-1 hour depending on how many drops I put in.
As for dead cartos...you have to try poking it through with straightened paperclip on regular carto and with large safety pin on premiums. Make sure you can get it straight through the carto going through the atty hole in the top through to the end of the battery end of the carto. You can also go up from the battery end to try to find the right path. Don't allow this process to squash the batting because squashed batting ISNT GOOD!! If what you are doing is squashing the batting or if the above idea doesn't work, try the following (can be done with regular or premiums): I find that with all premiums and more messed up regular Vapor king cartos use of a large safety pin works really well in fixing the insides of the carto. It can go straight through the carto even with the small premium batt end hole. Make sure that you can get the pin up through the bottom or down through the top...again, don't squash the batting. Another warning: don't let the atty wick (fabric at mouth end that is between the batting and the atty wire) pop all the way out of the batting when you are poking up through the battery end. If it doesn't come all the way out you can push it back in...and it doesn't need to be all the way in... as long as the wick is still somewhat in the batting you should be fine. If poking from battery end the batting may push up some because this does not seem to squash the batting and the batting can be easily (but carefully) pushed back down in place. Don't push the batting up too far though because you can disconnect the atty wires from the atty which will totally break your carto forever (yeah...did that. Ha Ha!) Keep trying. It is tough sometimes but try a few different angles and stuff before giving up. I have only thrown one or 2 cartos out due to not being able to find the hole or push a hole through.
If you have a direct hole in the carto from mouth to batt end through the atty/wick and you still have a tough pull...sticking thinner safety pins....not as long as the carto....and using the large safety pin to "fluff the batting": poking gentle holes in as deep as you can but making sure to not to squash the batting. Sometimes you can use the large safety pin gong up through the batt end, tilted to the side to go around the wick and atty and into the batting to poke holes to fluff up the batting. This has saved at least 4 of my cartos. Just make sure you have a lot of lighting, keep your eyes on the open mouth end, do this when carto is on the drier end, and move slow... when messing with the batting especially!!! Squashed batting has been the cause of at least 4 of my cartos dying. And I DID IT MYSELF. Consider this when using a syringe also!!!!!
Happy Vaping!!!!!