I was getting ready to do some minor modifications on my alto mouthpiece today and decided to wash it first since it appeared to have a cork grease build-up in the bore. What I got out of it was a ring of thin cork off the old neck that I had replaced. I couldn't believe something like that was in there - I had noticed some cork had come off the old neck but it never occurred to me that it could be in the mouthpiece. I guess no matter how long you have been playing, something new always manages to pop up from time-to-time. The thing is, I've played about five gigs with it like that and everything was fine. I don't play much alto now so I don't have to clean the mouthpiece that often but from now on I think I'm going to look a little closer at all of my mouthpieces before taking the horns out of the house.