Just curious about this. I tried it just the other day, after cleaning up the blade w/ Simple Green (had lots of pitch on it). Finished the job by honing w/ a fine diamond file. I filed only the faces of the carbide tips, three strokes each. Keeping a 90 deg. angle was easy.
The blade cut much better of course, but that may have been from the cleaning, not the honing. I *think* I could feel a sharper edge afterwards, but that may have been wishful thinking. I don't think the honing hurt anything, but it got me to thinking about the whole attempt, and whether I could lure the cognoscentes on the Wreck to weigh in with their opinions and experience.
The blade, BTW, was a middlin' Freud.
Please comment if you know anything about honing TS carbide.