Core 2 chazzing

I got a core 2 about a week ago and no matter what i do it gets stained instantly. It hasn’t noticeably affected the taste or harshness but I’ve heard most people are able to keep their cups in like new condition and i’d like to do the same. So far i’ve tried an iso q tip, q tip with water, and a dry q tip immediately after finishing 2-3 hits on blue session mode. Any tips?

Edit: Switched to the extra coil and haven’t had any staining not sure what was wrong with the first one but everything is working smoothly now.