If you wet the layer then lock pixels, the dry layer function will only partially dry. Not sure but it seems you get about 4 levels of drying.
- In one case I think I was able to partially rewet the layer, but I haven't been able to duplicate this.
You could use this to wet the entire layer less than normal and make your strokes diffuse less, but personally I'd rather adjust other parameters like Water (Watercolor Properties), Opacity (Brush Creator), or Absorbency (Visual Settings) to get the same effect, so for my workflow it doesn't seem very useful. But it's an interesting quirk.