Hi ejeffay, Not many suggestions as my GCC seems to have developed a chewing habit as well out of possibly hormonal frustration. Despite taking him to the vet twice about it (and in less than a week after it first started) it hasn't really helped. We are just trying to love him (not hard - he's a great bird!) and hope that he'll grow out of it eventually. He's high strung. Make sure your bird's diet is optimum (lots of veggies, pellets, beans, fruit/seed/nut treats etc), that he's getting lots of quiet sleep (10-12 hours) and that you don't encourage the plucking. We tell Charlie no chew and now he says it all the time (but doesn't listen). Stinker!
Anyways, if others have suggestions I would be happy to hear them. We've tried everything short of putting a collar on him.