If your cham is comfortable being handled Blow on it with quick hard blows at different angles which may dislodge a stuck area. If that doesnt help, what i do is is get a small bowl with bottled water and a few qtips. I get him comphy on my chest covering him with a towel until he feels safe i let mine fall asleep. Then i gently rub a wet qtip and twirreling it and discard before trying it again. I had to do this because my cham was grabbing his crest and digging and i was afraid he was going to reinjure his crest.