Purification wand. A wooden stick up to a metre long with streamers of white paper and/or flax attached to the end. It is normally kept in a stand. In a movement known as sa-yu-sa (left-right-left) the priest waves and flourishes the haraigushi horizontally over the object, place or people to be purified. An alternative is a branch of evergreen (e.g. sakaki) with strips of paper attached (o-nusa); the smaller version for personal use is called ko-nusa.
A Popular Dictionary of Shinto. Brian Bocking.