I have done this for many years. I tie them up many times that they are not even worked. I tie them up before and after they are worked.
We live on a busy US Highway. I will unsaddle a horse out in the arena next to the highway (farthest point away from the barn) and let it stand for a good while. I never finish riding and then take them directly to the barn to be unsaddled and turned out. It is just like the horse that is ridden out of the arena after a class and put away in its stalls. It rewards leaving the arena and makes them anxious to get out of the arena later -- sometimes to the extent that they prance and dance if they are the last horse to leave. These are all man-made problems.
I, too, have had to tie horses up for days and they acted like it was just another day at the office -- which it was. Absolutely nothing bothers them. They are just as ready to leave the barn or the ranch as they are to come back.
I would say, if you have horses that are in a hurry to get to the barn or hesitate leaving it by themselves or hurry to the arena gate, they could really use this type of schooling.
The benefit is only gained if the horse is standing quietly with a hind leg cocked when you put it up. If that is 15 minutes, the benefit is fully reached. If it is not before 3 hours. Then that is how long it sould take to reward him with turn-out