I use Liquinators from vaporescence, got the 3ml SS and AL just ordered another AL and the 2 that I do have work great so far, I have not boogered up any O-rings yet...
I start out by taking the tank apart and wash it out with hot water, then I drop all the parts in a small bowl of 91% alcohol for a few minutes while I punch then condom fill the fresh cart. While filling the cart, slowly boge has some tight filler in there lol, I take the parts out and rinse them off in some warm water then dry them off with a paper towel. I then put a few drops of juice on the inside of the tube, give it a swirl or two on both ends and install the end caps, around this time the cart is almost filled and ready to go in so I blow out the cart and leave the juice on the outside on it as a lube while pushing it in far enough to fill the tube up. After filling, I push the carto all the way in with a Calabash or Vase style drip tip, they seem to stop on the tank just before its too far. A couple times I had to adjust the angle of the carto a bit because it seemed like it was stuck but a little patience and they find their way in. I agree with DRLyman about holding both end caps while pushing the carto in to its final position, they will blow off if your not centered lol.
to DRLyman: GO BIRDS!!! and not soon enough Phils!!!
I ordered with the last tank 3 extra O-ring kits just to be safe because I know its only a matter of time until I rip one, but they are cheap and its only rubber. The tank locks together in just a couple of minutes after finishing up, it is very tight and I had 0 leaks so far. I carry it in my pocket at work and pull it out of my pocket by the tank and it never moves. I usually run 3ml of juice 2 times on a single cart then replace, they seem to get muted at the end of the second filling, I really have to twist hard to break the tank apart after they set up. I assume they are the same style tank and Im going to check out the J tank and maybe order one too haha.
Forgot to add that I use a punch that I got from evaporclouds, works great and does not pinch the carto. I usually put in 3 small holes instead of 2 bigger ones and found it to work great so far.