Just read your other post. Apparently you can dunk them in cold water which cools the breast bone. It worked last year the 1st time she went broody. 2nd time it didnt, so I borrowed a dog crate. I left it in the run so the other chicken could still see her. Proped it off the ground with some bricks. Gave her food and water. Then at night I would take her out of the crate and put her on the perch in the hen house, then in the morning when I let them out. I put her in the dog crate again. Did this for about 5 days. Cured her. I didnt put any eggs in with her though.
She started going broody again a couple of months ago and I tried the water treatment but it didnt work. So I borrowed my friends dog crate, Im pleased to say that mine is back to normal. Till the next time. She seems to go broody when the crows are about. Particularly at there nesting time. They have got in the hen house and pinched the chicken eggs.
Not sure what breed my one is but reading up it would appear that some breeds are more prone to being broody than others.