It's got similar properties to sage, popularly being used as a purifier of places, objects and people to encourage positive energy and dispel old and negative vibes. It was often used in Native American sweat lodge ceremonies, where the sweet scented herb was sprinkled onto the hot rocks to improve the energy inside the lodge and fill the air with a sweet aroma.
Traditionally it was plaited into long braids - ideal for using during cleansing, prayer and smudging - and is still often found sold like that today. Belief has it that when sweetgrass is burned, a prayer is sent to heaven on the smoke. It's properties make it ideal for using in quiet moments of contemplation, as well as when wanting to create an air of purification.