Taken from Godey's Ladies Book 1855
-To clean hair-brushes, put a spoonful of pearlash into a pint of boiling water, then fasten a bit of sponge to the end of a stick, dip it into the solution, and wash the brush. Next pour some hot water over it, and dry before the fire.
Meanings of Word or Phrases used
Pearlash- This is a refined form of potash.