I did the treat thing for 3 months straight, everyday.  I was the only one to give him the treats.  When I give him treats I would break them up small so that his beak would have to touch my fingers in order to get the treat.  He would take the treat fine without trying to bite but thats the only time he would.  After 3 months of doing this he still was the same way.  I go up to his cage everyday and talk to him, tell him hes a good boy if he just sits there and tell him no when he lunges.  I try holding my hand close to the cage without moving fast to show I'm not going to hurt him.  This last a while but now he reaches through the cage with his claw to grab my finger to pull it in and bite me.  So these things havent worked.