I understand your frustration. Feather picking is annoying and frustrating and it's that way because it can have many causes, and nothing works for very long. Years ago, I had a serial feather picker, an EE hen called Flo. I tried everything, and one day I stumbled onto a nutritional supplement called Forco, and I thought I had discovered a miracle. It seemed to be working. I was so entusiastic, I started a thread
https://www.backyardchickens.com/th...cure-for-feather-picking.697052/#post-9455600
The thread grew into lots and lots of pages, and lots of people chimed in with their experiences and cures, and by the time the thread had run its course, we were all back to our original frustrations. Feather picking has no magic cure. There is no one special secret to stopping the behavior. I wish.
You might skim through the thread. At least it has in one place just about every device and supplement you can try. Something might work, if only for a little while.
Now I have a new serial feather picker, Flo having died several years back, and I'm doing with her the only thing that's ever really worked for feather picking - pinless peepers.
This new picker is also an EE hen by the name of Louise. I installed the peepers on Louise a couple months ago when she was following other chickens around and snatching feathers from them. I removed the peepers about two weeks ago because Louise can't seem to work the nipple waterers wearing them. But she lasted all of three or four days and she was stalking the other chickens again.
So I put the peepers back on her and she hasn't picked any feathers. But I need to have an open container of water for her so she doesn't die of thirst.
Some flocks never seem to have this problem while other seem to be cursed. I suspect breed has something to do with it. I also suspect it's seasonal and hormonal, picking up in spring and summer and dying back over winter.
I keep a good supply of pinless peepers on hand and am ready for it to start up in spring. And it doesn't disappoint me. It does.