This is not a preventive measure but is effective if you've already been hit by a malevolent spell. Make sure the scalp is cleansed as well as the hair.
Help remove stagnant or negative energy from the mind and body. 
Purify thoughts, uplift the psyche, and calm "hot" or overwhelming emotions
Restore balance realign spiritual and energetic well-being
Use as Preparation for new roles, new phases of life, or to clear a path for spiritual or personal growth
Slowly pour the mixture over your head. Visualize all negative energy being washed away
Dry Naturally:
Allow the mixture to air dry on your skin to fully absorb its effects. 
6. Anoint Yourself:
After the ritual, you can anoint yourself with a spiritual oil, such as white lavender oil, to seal in the positive energy and promote peace