I have a coop with 21 Buff Orpington/Barred Rock crosses. Buff Orpingtons are famous for being broodies. As they each go broody, I give them some eggs to hatch. They don't need to be chicken eggs by the way. Mine have hatched out turkey eggs, Guinea eggs, and duck eggs, in addition to chicken eggs. I hope to try goose eggs some day, LOL. But anyway, they set on the nest until the eggs hatch, at which point I take the babies away to raise myself or sell. My hens still insist to sit on their empty nests, so I take them and put them in a dog crate that I keep in the coop for that purpose. I give them a tray of food and water, and lock them in there. It varies by hen, and how long she's been broody, but 3-5 days generally does it. Locking them in this crate is the only "cure" I've found that works.