Honing a blade still "moves" the blade close to what you want: a blade that cuts well. It's not correct enough to have spawned the original phrase, but it's not completely absurd, like saying, "should of" instead of "should've" or saying "I could care less" instead of "I couldn't care less" - the first of which is nonsense and the second means the opposite of the intended meaning.

"Hone in on" is at least mildly in the correct direction.