If you go to the main page of the web site,
www.thogamecalls.com and then go to the Tutorial Section, you will find two great links. One is on filling grain and using CA glue for a finish and the other is a link to Russ Fairchilds website which has more than you would ever want to know about finishing.
I use Teak Oil on my hunting calls, and you can get Watco Teak Oil at Home Depot or Lowes. On my other calls I normally use a CA Glue finish.
If you learn to turn acrylic, you wont have to worry about a finish
Al @ THO