Okay, just a quick background on my bird first for a reference point: he is a re-home who spent his first year in a pet store and the next year and a half caged almost all of the time in his first home. He was 2 1/2 when my husband and I adopted him so we didn't have the opportunity to try to socialize him properly when he was very young.
I want to socialize him but he is aggressive toward visitors. I have read Michael's blog article about how to socialize a parrot and we have always started out with step one, which is "ignore the bird", but step two is "let the bird loose" and this is proving to be the problem.
I had my parents over to visit multiple times, they would always ignore Bubba for a while, then later I would take them in to visit and they would just talk to him in his cage. My sister visited multiple times and we did the same thing. He seemed okay with this.
After doing this for several weeks I thought I'd try to let him out of his cage. An hour into my parents' visit I opened his cage. He was in the den and they were in the living room, but he immediately flew from his cage into the living room, directly at my mother's neck. He landed on her shoulder and I grabbed him really quickly before he was able to latch on to her skin but he was definitely not just going to say "hi" because he managed a bite before I was able to grab him.
This was discouraging so I didn't let him out again while I had visitors but a few months ago when my sister was here I thought I'd give it another shot. This time as an intermediate step I moved him to a travel cage and let him sit with us in the living room about 10 feet away from us for about an hour. No one was approaching him, he was just hanging out. I finally went over and opened the cage at which point he immediately flew out of the cage and launched himself directly at my sister's neck. Again I grabbed him but he did get one bite off before I was able to remove him.
That was pretty much the end of letting him out with visitors, since I can't have visitors being attacked by my bird. He is a very, very sweet and cuddly bird with me and my husband. He never bites. I do positive reinforcement clicker training with him every day and he knows several tricks as well as flight recall. He really is a very good bird, and he is a tame bird, except for when I have visitors and then apparently he is a flighted, monstrous ball of aggression.
As a final note he is very good with the vet. He sees two different vets and he steps-up for them, he lets them give him head scratches, he never bites! It's just visitors in the home that are a problem, apparently.
Any advice is appreciated, I can't trust him to let him out when I have visitors so I don't really know how to try to socialize him because of that fact.