I wouldn't ever just try to wait broody out to go away on it's own. It's really unhealthy and stressful on the bird. Break her or give her some eggs to hatch. The stock tank might not work very well as she will still try to make a nest in anything solid bottomed. You really need to have her in a real cage that is up in the air. Make it so the air can cool her underside so she can't think she is warming anything.
True it might be less common on production breeds but it still happens.
True it might be less common on production breeds but it still happens.