Just attempted my first carto rebuild until the co-op order comes in. Was definitely frustrating, but now it works better than it was after using it about 10 times (only hot water and sonic wash in between). The only thing is that the cotton seems to have to be pushed in farther, so it doesn't hold as much liquid (mine never held 3mL. Maybe 2-2.5mL). When I pull it back up to where it was, I get burnt taste, so I just leave it pushed down. Awesome flavor and vapor again, so I'm a pretty happy camper! 
Oh, and I used some click pen guts taped together instead of a stir because I couldn't find any stirs laying around the house. LOL
Oh, and I used some click pen guts taped together instead of a stir because I couldn't find any stirs laying around the house. LOL