Dunking a broody hen in water sounds extreme, even mean. I found the easiest way is to confine the hen to a wire-bottomed cage -- WITH food and water!!! But nothing else but a stick for a roost. Hang it from the rafters or set it up on sawhorses or blocks for maximum airflow under her. After 3 days the hen should be ready to return to her flock. We use an old parrot cage on a metal stand, we call it the Broody Buster.
But why do you want to break her broodiness? She sounds like a good Mama, staying with her chicks for 7 weeks (it's not "abandonment" at that age, they're old enough to fend for themselves and feathered enough to keep warm). And I'd trust even a broody hen to keep from starving herself.
I don't understand what the logging has to do with not wanting a hen to set eggs, will the trees be falling on the chickens? Even so, I would urge you to use a kinder method to break your hen's broodiness!