What is Black Salt used for? Some witches like to pour this salt on window frames and doorways to protect the home. When you cast a spell, pour a pinch of Black Salt in each corner of the room, before beginning the ritual, to scare away any negative entities. Place it on your altar to add power to your spells, meditations, or daily wiccan practice. Use it for cleaning or consecrating crystals, amulets, tools, circles of protection, and more.