Indigo squares good for rituals. They are used for wash and aura wash to absorb negative vibrations, clarify, purify as well as for protection against the evil eye, attract luck and to raise spiritual vibrations. In my upbringings these types of rituals are performed to dispel negative energy we may pick up from people and places or energies left in our homes or worse, those low energies we cultivate as our own such as hate, negative self talk, envy, etc.