This salt is made for protection. There are so many ways you can use Black Witch Salt.
Sprinkle it around your front door or your property to protect yourself from negative energy. 
Use in your own jar spells!
Put your salt in a bowl and place it under your bed. This will help protect yourself from your own negative thoughts and/or negative thought patterns. 
Use this salt while you meditate to protect your energy and chakras. You can focus on certain chakras to increase the intentions. For example, you meditate on your third eye to protect it from your own fear or whatever is blocking it.
Make a circle of this salt around you for protection during rituals. 
Keep around the house to ward off negative spirits.