Jeff,
You asked how it sounds.
It depends on where I rub and how hard. If I rub it down the middle of the grooves, it is kind of a harsh CLACKCLACKCLACK, especially if I bear down too hard. But if I get over to the end of the grooves, and use a lighter touch, it is more of a whirr noise, which is what I would guess I am looking for.
I think if I sanded the points between the grooves off to a rounder tip, it would be less clacking. This would look more like your call, with not so prominent ridges.
As I say, I am looking forward to your video to see what yours sounds like, and how you use it.
Good luck with the hunt. Beware stray tigers.
Walter