I arrived to late to get the in-progress pictures of this demo but it's pretty self explanatory. The tight sketch can be seen in the second picture in the top left if you're interested. A bleach technique courtesy of Don Brandes.
Step 1: Sketch out a tight drawing
Step 2: Photocopy sketch onto toned paper, ie - Canson's Me Teintes
Step 3: Use a brush that can get into a nice tip
* DON'T use any high quality brushes this is a BLEACH technique!
Step 4: Dilute bleach and slowly lighten areas as desired. Use as much or as little bleach as you would like, at this point it's all up to you.