What for:
Saving time is one of the mayor advantages of this technique
• Smoothing transitions between shadow and light
• Removing Strong Highlights
• Removing strong shadows
• Flattening light – so you can introduce new highlights and also shadows by manual D&B
• Smoothing median texture
• Straightening and tightening fabrics in clothing and accessories.
• Smoothing floors, carpets, grass and any kind of textured surrounding (as long as there’s no recognizable pattern)
• Straightening hair
• Removing blotches in legs and body
Experiment with it, and will lead to a lot of other uses.