OK, before I start this I am going to state that I did try to search this one before posting, but since one can not search for three letter words, it makes it much harder to find anything on this. I also looked in the WIKI, but didn't see anything relevant there either.

Anyway, my question is on celluloid scales, how do you know if they have rot or just need to be cleaned up? And can the rot be cleaned or removed and if so how?