Interesting , I was just going to ask if anyone uses Mitch's whirler and what they thought of it.
This seems to be a good page to see many of the whirlers available...
http://www.thefind.com/sports/info-dubbing-tools
Here's an easy way to make one.
Making the Easy Door Knob Dubbing Loop Tool - Volume 6, Week 39 Fly Angler's OnLine"
Chugger, just curious ...do you already own a Cal Bird?