Softening a Stiff No-Rinse BrushIf your brush begins to get stiff near the base of the knot due to excessive retention of shave soap, there's a simple fix:
Thoroughly immerse the brush bristles in water for a second or two -- just enough for all the air to bubble out of the bristles. Then give the water another second or two to soften the soap in the brush.
Then with thumb and forefinger, squeeze the base of the knot just above the handle as though you were trying to choke the brush knot. The pressure should squeeze excess soap up from the base of the knot toward the bristle tips. You will see soap lather emerging at the bristle tips. If you do this a few days in a row, you will easily and quickly make available for shaving that otherwise useless soap trapped deep in the knot.
UPDATE 8 June 2016: The preceding tip pertains to shave soaps that are somewhat soft such as the formulations that are typically used in shave sticks (which I, personally, prefer). If you use a hard shave soap, the soak time in water may need to be longer, and perhaps the water warmer to soften dried soap deep in the brush knot.