Hey there Mark,
I see your from Jeff City. I spent more than a couple of years outside of St. Louis and have a lot of family down around Salem and Rolla. Man I miss catfishing on the Osage! Go catch one of those big flatheads for me when you get a chance.
To answer your question, the sharpener itself works excellant on Grizzly broadheads. It is designed to hold the broadhead at a constant angle as you sharpen.(around 28 degrees for the grizzly). The real question is: Is there a stone or file strong enough to stand up to the hardened steel of the mighty griz?
Here's the problem/situation- the Grizzlys are factory ground at over 30 degrees and the steel is so hard that it takes A LOT of work to get them sharp the first time. This is because quite a bit of very hard steel has to be removed on the initial sharpening.
For that first, "out of the pack" sharpening about the only stone that will do it fairly quickly is an extra coarse diamond, and you need a big one. I'm going to get some large XC diamonds stones ordered this week but, my problem with diamond stones is that they cost a fortune and they will wear out. A less expensive way to "grind" them is, as Don mentioned, using wet/dry automotive finishing sandpaper on a piece of plate glass. Start with something very coarse like 120 grit then progress through 220, 400, and then 600. At this point they will be smoothly polished and fairly sharp and can be finshed on any standard India or Arkansas stone or you could just keep going with finer grits of sandpaper. Bill Howland uses the sandpaper through 2000 or 3000 grit for an insanely sharp mirror polished edge.
-Sharps