Smudging is the practise of releasing a herbs ‘magickal’ energies through fire, to create a purifying or stimulating (depending upon the herb) smoke bath. Originally used by the native Indians of America for banishing evil spirits, smudging and sage cleansing rituals are now used worldwide and are commonly advocated as an effective means of banishing unwanted spirits and other negative energies.
Sage smudge sticks themselves are simply bundles or boughs of sage bound together to create something akin to an incense stick, and once lit the purifying smoke should be trailed throughout the contaminated area, allowing it access to all nooks and crannies, in a bid to force the evil spirits (who are said to detest sage) to move on.
Sage cleansing rituals are also said to be effective at cleansing individual items or people, this can be performed in the same manner as above, but by cleansing the item/person in the purifying smoke, or in the case of items by storing them with boughs of sage.