Here we have Blender Trim Brush tutorial: friendly reminder on how to recreate a Zbrush famous Trim Brush.
For this task, we’ll use Blender Scrape/Peaks brush.
Based on videos by Rocz3d and Paul Gerashkin
http://www.youtube.com/watch?v=5VfUEcQrHNQ
http://www.youtube.com/watch?v=JWx5SMwQYOA