My suggestion would be to send the bird for a Reiki Treatment, which works fantasticaly on animals, I am a Reiki Master operating in Brakpan if this is close to you Icould offer this service, alternatively I would suggest to use crystals, a good combination would be a Citrine - which blocks all negativity, Howlite - to calm down aggressiveness and Snowflake Obsidian a stone of purity, balances body, mind & spirit, you could see if you could buy them already pierced so that you can hang them on a chain inside the cage, otherwise place them together in a pouch and hang very near to the cage, I promise you that this will bring a 100% turnaround in your parrots temperament. You are welcome to email me should you need further assistance. Kind Regards Gabriele