Two of my hens were broody for 8 weeks. As a last-ditch attempt to break their broodiness i placed one hen in a small coop, outdoors for 4 days. During that period she looked pretty cheesed off. When i released her (my hens free-range during the day time) she immediately went back to her good- old self (and even let me pet her, which she would certainly not do when she was broody!). It seems that temporary "solitary confinement" did the trick. Just thought that i would share my experience .