About 15 years ago I bought a whistle that was marketed by MAD calls. I lived in Virginia at the time, and it worked great. I was getting responses 400-500 yards away. I had no complaints and recommended it to everyone I knew.
Now I live in NC and these birds will not gobble at the whistle! An owl hoot works, but not the same whistle that worked one state away!
I'd say give it a shot; they are only $5 or so. The nice thing about it was the fact that other hunters didn't hear it when I was scouting and as soon as I found a gobbler I would shut up until the next AM.