You can handle a dog without blowing that irritating whistle every 30 seconds and screaming at the dog. None of me dogs ever new what a whistle was and never had a problem handling my dogs at the blind. I good dog that knows how to hunt doesn’t need at that. I never sent my dogs on long crippled birds by themselves. I always went with them. I always kept my dogs in sight or earshot. Especially if it was kinda warm. To many gators in the marsh. The biggest this is a dog needs to be able to watch everything that is going on so I always had them where they could see 360. It does help when a dog hunts the same blind everyday. That makes it a lot easier on a dog. Did they always get every bird every time. Of coarse not. If they didn’t get it, when the hunt would slow I would send them to get the missed birds. Most people that have highly trained dogs need to be highly trained to work the dog. I just gonna leave that right there.