has any one ever used it .book says queen ands drones can not come or go. is this a way to stop a hive from swarming?
Reducing the entrance(s) to the point that only the workers can come and go is a very good way to strangle a hive to death.
The idea of the quarantine entrance is to keep swarms from obsconding after capture. It is meant as a temporary solution to a common problem. Long term it is a death sentence.
I have had a few around over the years. They are just an excluder for the entrance. You can accomplish the same thing by putting an excluder on the bottom board. They cause problems because the drones can't get out and they pile up and die. But they are useful for a short time when installing a package or hiving a swarm because the queen can't get out for them to abscond.
I have also heard some use them at the end of the day to collect drones at the front of the entrance for semen, etc. You know by this trick that you are collecting older drones who are primed to mate.
As for swarm control. No...bad idea.