favorite is always cardboard wheels on a cheap grinder. Gotta be careful though. they are dangerous., rada we have on the filet table in AK. So far not all that impressed. Though I think it may be worn out. I try to filet only a few salmon, hit it again, and so on. But Its so wobbly I bet I should buy a new one.
FWIW Havalon makes a filet knife. Blades not that cheap but it sure isn't dull
