My recommendation...Get that gos flying and killing. Get it more exercise and let it take some aggression out on something.

Short term; Use a spray bottle to spray down your gos with water.

Long Term; Have tidbits readily available. When your bird sits quietly on the perch with out bating...any perch…give a “click click” noise with your mouth (or what ever noise you want) then give it a little tidbit. Continue this....over time your bird will learn to sit quietly longer and you will be to stretch out the time you provide tidbits for your bird for sitting quietly. I hope that helps