Dog collars - prevent overnight barking

[ALDuke]

I have a coworker that has a dog on his farm. She will bark at night, he can stick his head out the window and she will stop for an hour or so, then start back up. No telling what she is barking at, but I mentioned a bark collar. Any suggestions? I know they have collars that don't shock, do they work? Also, the dog is about 50-60lbs. Any help would be appreciated, as he is nearing the point of giving her up. I'd hate for his wife and kids to find out that was going to happen.

[gsdraven]

Why is she outside at night if it's not to alert to things?

That said. I have a Finnish Lapphund foster right now who will bark for HOURS straight without getting tired or hoarse.

He wore one of

Amazon.com: Petsafe Premier GentleSpray Citronella Anti-Bark Dog Collar: Pet Supplies

Amazon.com: Petsafe Premier GentleSpray Citronella Anti-Bark Dog Collar: Pet Supplies

for a couple of nights and he no longer barks all night long. He actually doesn't bark at all anymore, just whines, even though we aren't putting it on him. No shock or vibrations, just a spray of citronella to interrupt the behavior and it's unpleasant enough that most dogs won't keep barking.