I still hunt alot, and the grunt tube always stays around my neck. I use it when I jump deer, and when I spot deer before they spot me. When I jump deer they stop and look back, only a handful of times have they walked back towards me.
One time I was still hunting this hardwood bowl and I spotted a nice buck down below me, I gave a light grunt, he glanced up and turned right for me. He gave ma 30 yard shot . . . but I blew it, lol. So I guess you could say the actual calling was successful, lol