The pic speaks for it's self, I use a blade from a box cutter, put it in a vise, break it off with a pair of pliers so I can control the excess, leaving enough to extend out the "Back" so it can be used as a handle to adjust the blade. I dull all edges that are outside on the "Handle" portion so you can't get cut on that side.. then I insert the blade in the dowel cut, adjust it to the binding to be scraped so no wood is marred tighten the wing nut and scrape away. I also wrap the handle with duck tape to protect the side (Or top) of the guitar. Works GREAT! When it gets dull, I get out a new box cutter and repeat!
They won't give me a patent...BOOOOoo!
Ray :)
A little addendum, I have a friend who does none of this, he uses a piece of plate glass from a lab microscope (Because he has many of them) and scrapes away...it woks for him, not big enough for these big Ol hands of mine! :)