This tool finds all Guide Groom SOPs within a groom object and recaches them in order of dependency. Recaching ensures that changes made to the input geometry of a Guide Groom SOP are reflected in the groomed output.
For example, if you groom your character and then go back to the object level and change the density of the fur, you can click the the Recache Strokes button on the Guide Brushes tab to automatically reapply all strokes.
This is the same as clicking the Recache button on each operator.
Alternatively, you could use this to change the input character and reapply strokes.