Black Lava Salt is sea salt combined with activated charcoal. Black lava salt is used in magick to absorb and trap negative energies. Salt is used by many to absorb energy, and charcoal is well known to absorb toxins.
To rid your home of unwanted energies, sprinkle black salt around your house and then sweep it out the door.
Do this right after someone you don't want returning walks out the door, to ensure he never comes back.