Blue Sage (also known as Grandmother Sage) is a purifying herb with wide medicinal and magical applications. Blue Sage is often used for cleansing and purification, it provides spiritual strength and sometimes it is also used during exorcism rituals to remove the malevolent spirits.

Blue Sage is named for its abundant blue flowers, but the leaves are also have a blue-ish. It has thin leaves and a fragrance that is similar to lavender.
Smudges may help clear the air, scientists have observed that sage can clear up to 94 percent of airborne bacteria and disinfect the air. Also, when sage is burned, it releases negative ions, which is linked to putting people into a positive mood. 
Smudging requires simple ingredients like matches, smudging herbs, and a smudging bowl. Before you start, remember to open a door or window, because the unwanted energy you are trying to clear must have a pathway to get out. First, light one end of your smudge, allowing it to catch fire and burn for several seconds. Then gently blow on the lit end - the smudge will begin to glow and smoke. Lay the smudge on a heatproof bowl to catch the ashes as it burns.