Although commonly used to mean washing yourself or a ritual wishing, among alchemists it means to wash away what is impure through repeated cleansings, that reducing the matter you have to a pure state.
Readers, please enjoy this guest blog post by Sandra Kynes, author of several books, including The Herb Gardener's Essential Guide, Plant Magic, and the new Witches' Encyclopedia of Magical Plants, among many others.
Although a few old books...