Hook sharpener
 

I bought a hook sharpener last week that didn't come with any instructions but I thought I could figure out how to use it. It's a small rectangular stone with a tapering groove on each side about 2/3's of the length of the stone. I've become very adept at dulling my hooks. Can anyone, from my description, tell me how to use it OR recommend a good, easy to use type? Thanks for the help.

use the groove to sharpen the point.