I just got a used Yamaha yas 21 alto sax that I am learning how to play on. The previous owner obviously did not clean the inside because there was brown cracked stuff inside the neckpiece and some green stuff. I cleaned out all the brown stuff using a cloth with a vinegar water mixture. However the green stuff is still there. Anyone know what it is? Some is also on a pad. Will it affect the playability? Can I get it off the pad without replacing it?