Just an informal survey....
Do you use one? All the time or only during/near the rut?
How loud or quiet do you grunt?
Do you find it effective?
Myself, I have mixed results. The other week, at dark I had a 4pt in front of my stand. I was ready to get down but didn't want to spook him. Whistled a few times, hissed a few, no effect. Grunted a few times, he would just put his nose in the air and go back to grazing. Had to runt ridiculously loud for him to finally realize something was up and walk away. Granted, our rut is just getting started this week or so.