Hi there. I recently had that problem with my nose peircing. I don't know if it would be the same thing. I too was washing it and putting neosporin and all kinds of stuff on it. I called the place where I got it done and they said that I'm suffocating it, and not letting it heal properly. They told me what they thought I should do and it cleared right up. Maybe it will help for you.
Try washing it twice a day (no more, no less) with Dial anti-bacterial soap. Put nothing else on it...and DO not touch or play with it at all. Don't know if it will work with the cartlidge or not. Good luck