I have had constant broodies too this year. I did more research since I was having trouble breaking them. I realized that I needed to keep them in the cage overnight, too - since even if you put them on the roost, they seem to find a way to get to the nest regardless of what you have done to block them off at night. Each time they make it to a nest, it seems to "recharge" the broodiness. Cages up off the ground supposedly work best since air flow improves to cool their heated chest and legs. When I have had multiple broodies, though, I haven't noticed a difference between keeping them in a temporary run and keeping them in a wire cage off the ground.I've lost count of the number of broodies that I've had this year. I've run out of pens to keep them separate in. I finally have one hung up in a cage on bungee cords. How long is it supposed to take to break them of being broody?
Longest time in a cage: 5 days, most of them break on the 3rd or 4th day.
Best tip: if you can, put them in a temporary run for a bit during the day and throw them scratch - anything to encourage normal behavior.
I have tried a cold water sitz bath, but it didn't seem to accomplish anything on the three different hens I tried it with. I have not tried dunking their entire body in cold water.
I have found I have to be extremely diligent about removing potential broodies from the nest, and when I am at work on long days, I seem to get a broody since I can't collect the eggs.
Right now, I have been broody free for almost 36 hours!!!