White sage is an organic antimicrobial. Blue sage also known as "Grandmother Sage” is a purifying herb with broad medicinal and magical applications. Blue Sage is commonly used in cleansing and purification purposes, as it provides spiritual strength. Also they both have been shown to keep away bad energies. Beliefs that burning sage clears out spiritual impurities, pathogens, and even insects have been fundamental to the practice of smudging.