intensive and long tedious tasks of draganising will be an understatement. I've tried it, and it took hours. You can try searching for how to do it step by step in deviantart.
It's just contrast that gives you the perceived sharpness. Try playing with the level and contrast. It's not much different than running the image through a photocopier. Of course, your original image needs to have a certain level of contrasty detail before you could pull this.
Just for fun, i downloaded a portrait image from Wikipedia Commons to use as an experiment. This is a photograph of Robert De Niro. The image was first converted to b/w, then post processed.
Here's a comparison between the original and processed.