The secret is to maintain the same angle on the blade during the process.
I can pretty much make any blade you have shave the hair on your arm freehand.
If you need a blade "dangerously" sharp, I can direct you to a business in Stillwater ok.
Dave Mcrosky and his brother produce some of the finest knives available at the lowest price in my opinion as well as others.
When Dave sells you a knife, you can fillet the ink off of a piece of paper.
I called bullcrap and went to his house.
I can assure you it's true and have done it with the two I now own.
He will sharpen the knives for free as a lifetime warranty if you hand carry them to his house, or free if you pay shipping both ways.
He will also sharpen the knife you currently own for a small fee.
For the record, I have skinned two elk with my elk skinner model, and it still shaves.
My home computer crashed, but I will post pics when I get it back, or go to Mcrosky knives.com.
That may be spelled wrong, but google will correct