I think there's too much technique in the conventional form of "hair whittling". I don't really care how sharp a knife gets, when the hair is so curly that it basically coils up, it's not going to whittle as easy when you hold it out in front of you--even if it does, because the way the hair is curving I just wind up slicing clean through the entire hair at an angle versus slicing anything off of it.
The way I do it is I hold the knife's edge straight up, and then I insert the tip of the knife through the radius the hair forms, and then drag it over the edge. Only takes a little bit of adjustment, but once the edge catches the inside of the curl it will fillet a good sized hair two or three times, and the edge helps straighten the hair out so it actually fillets instead of cutting right through.
Most of the time if it's "hair whittling" by my standards the hair will catch the edge, and stick to it as I pull, splitting the hair in two; then I can keep doing it to those strands once or twice, but past that my edge angles are too obtuse.
If it's just a little dull, then it will just take big "scallop" cuts out of it, and if it's only shaving sharp it will just scrape little bits of hair into curls--kind of like you'd see metal chips forming on a lathe.
I sharpen on a Norton 220/1000 and then strop ( a lot ) on MDF loaded with Cr0--by a lot I mean more than it really makes sense to ( 400 strokes on my S30V Kulgera last night to get it hair whittling ), but I haven't had the cash to buy a higher grit stone yet so I just spend extra time on the Cr0 and it gives me pretty decent results. The polish has lots of scratch marks from the 1K left over so it's not really mirrored, but past that it is very polished and I can see a faded reflection on the edge face.
Anyway, do any of you guys have video cameras to show how you whittle hair? It doesn't need to be high quality or anything since it's not really a "proof of whittling" but more just a demonstration on how people do it. I'd be really interesting to see how some of the sharper edges here handle curled hairs when whittling them like a stick--I can only whittle these by dragging the inside of the curl along the edge, but I have a feeling a sharper knife wouldn't be so easily defeated by a slight curve.
Anyway, so as far as hair "whittling" goes, this is my hierarchy and an explanation...
Hair Filleting - You can fillet the hair as if it were a fish, taking long slices out of it over the whole length of hair
Hair Scalloping - You can fillet the hair, but you can only slice out small portions like 1 cm or smaller, so it just leaves scalloped cuts in the hair
Hair Scraping - The edge catches the hair and is scraping off pieces similar to cat-tail chips you'd see coming off a metal lathe... Sorry, I don't know any other way to describe it coming from a machinist background.
Anyway, that should answer both phrasings of the question.