This last go 'round with Myrtle we didn't get her in the box until nearly a couple of weeks in. We had tried a small tractor coop we held onto when we built our permanent coop and run. We didn't have any bedding in the tractor coop and couldn't really nest except on hard ground. That works with...
For ours, the issue seems to be not being able to nest. I think that's the main benefit of our broody buster "box" with the wire bottom. It sits inside our 8' x 16' run so whoever is in the box is safe from predators.
We have an Australorp who's a tough one to break when she gets broody. We put hardware cloth in the bottom of a small dog crate, put the crate up on some landscape blocks, put food and water in, and lock her in for a few days. That way her tummy gets cooled off, she's just enough uncomfortable...