My brother in law makes these in exactly the same manner. The only thing different is that he puts a piece of rubber over the mouth piece to act as a stop so that when you stick it to your lips, the opening of the call lands at the same place every time. It definitely makes them easier to use.

This is fast becoming my favorite call. I killed this year's first longbeard after two yelps. He gobbled, I walked to him and yelped and he cut me off. I walked about seventy yards to a good crossing and sat down and yelped again. He cut me off again and within a minute he was flopping on the ground. The whole hunt lasted about five minutes. I sure wish I could do that at will. I've hunted like a maniac for the past two weeks and haven't connected again yet. Lot's of gobbling, hens and hung up birds.