The Power of Gray - The Photoshop: Professional Retouching and Compositing Tips, Tricks, and Techniques - page 106

Figure 2.30
You may also find that there are areas of the dodging and burning where you want
to reduce the strength, or even remove it completely; this is where we use the 50%
foreground color that we prepared in step 3.
8. With a normal soft edged brush and the 50% gray foreground color, paint over
areas of the dodge and burn layer to remove or reduce the dodging and burning. To
remove it completely, paint at 100%; to reduce the dodging and burning by 50%,
change the opacity of the brush to 50%.