I have some factory ones and I have syringe 3ml home made ones...I take the inner caps out, then hold it under a running faucet with HOT water, this is all you need to do. Let the water fill it, then flip it and shake the water down and out. Keep doing it, you will see the juice in the reservoir is gone almost immediately, now for the wick. The wick will lose about 90% of all the juice thats in it from doing this. Burn it till the coil is looking good, wash it out again, then burn it and wash it one more time, now that carto is clean as a whistle. But I don't like my wicks being water soaked when I refill. So take a pair of tweezers, reach down inside and gently hook and pull the wick up real easy.(both sides) Also without the caps in place, the ceramic cup can be pushed to one side or the other real easy, for access to your wick from the opposite side. Then just touch the wick with a papel towel and it will dry nice nice. Sometimes I dont bother even drying the wick and I still have had good luck. For refilling, go to your local CVS, head for the pharmacy tell the pharmacist you need a 3ml BD Syringe with the tip. I bought 6 yesterday they were .17 cents each. Makes it ALOT easier to fill those cartos. I have some of those cartos that I have refilled well over 10 times, and they still work fine.