Plax, Thank you for helping and posting this video, this is exactly right. This method was taught to me by a guy who passed away who called himself the parrot whisper.
I beleive his name was Ken but forgot his last name, he was wonderful with parrots of any size or behavior issues. He would really enjoy the meaness Macaw or parrot an owner would have and would not dare to even attempt to hold the parrot or even touch it.
You can most likely find his old videos on youtube.
This method really works for Macaws who like to bite but you have to repete this method over and over until the Macaw gets it. Best of luck to all and again thank you Plax. Joe