hole in chest from plucking, help

I take care of 3 cockatoo's. The moluccan is a chronic plucker that keeps a big hole in his chest from gouging. He takes antibiotics everyday to prevent infections and his water is treated w/ "pluck-no-more" solutions, plus he wears aq little tutu to cover the hole in his chest, which he bites through in no time. I haye read about collars you can get for this problem. Does anyone know where I can get one of these? These 2's are kept in a large room with a large sliding glass door, windows, toys, etc., but the owner,a doctor is gone at least 8-10 hrs a days and the birds are alone. I would appreciate any info/advice to pass along.
thanks so much.
gabby

ps
I own an african grey that rules the house

We honestly cannot tell you advice unless these are met:

Size of cage they are in?

Are they housed together?

How much attention they get?

Full spectrum lighting?

How much out of cage time?

How many toys, what kind?

My Umbies have about 30 toys in their cage, and they are in a GIANT double macaw cage, 80"long, 6ft tall and 40" wide. And they're only in there5-6 hours a day. My Scarlet macaw is in a double macaw cage 72'' height, by 64'' length, by 32'' depth, and she hasabout 16 toys, a boing and a rope twirl perch and several perches as do my umbies. Our mollucan has a petite cage of 36x28x60" PLAYtop cage and she is out ALL day long and has 16toys to chew and play with. Our quakers are in a flight cage thats 30"long and 21" wide dome top of 35" and they have about 12 toys each, two wuakers share the cage.

When and if they are ever out of the cage are they just on top of the cage? What about playstands, and things to motivate their mental abilities and physic?

Pluck no more will not help if any of these is the problem. It only helps stop habitual problems, not behavior and environmental problems.

Mercedez

Gabby

Have the pluckers been seen by an Avian vet?If so they would be the ones to fit them for a collar.There are also sock buddies that I'm told help.I have quite a flock and also have a plucker.It's a B&G Macaw named Buzz she's now 14 years old and has been with us for 4 years.She has had every test we could think of.Buzz came from an abusive home of 10 years and it's heartbreaking to see her with feathers one day and gone within the next couple days.It has been ruled habitual plucking so I do know what you are going through.She has plenty of toys and lots of interaction as well as time out of cage that they have renovated the birdroom with her other Macaw friends.Looking for answers too!

Marcia