The herb mugwort (Artemisia vulgaris) is used to charge, enchant, and cleanse a witch’s mirror.
Mugwort conjures psychic ability, the understanding of dreams, and the heightening of the imagination. Always have this herb if you have a mirror. Using fresh or dried mugwort, you can create a brew, just like making tea. Submerge and rinse a clean cloth in the infusion and wipe the surface of your mirror.
Mugwort can also be burnt in dried form, and the mirror passed through the smoke to invigorate the vibration.
From my book- Becoming the Witch the art of Magick