Four Thieves Vinegar is essentially a liquid neutralizer which may be thought of as a super-charged version of Clorox. It may be poured directly from the bottle on any area you feel is contaminated with spell work or hexing, or it may be diluted in water for hard surfaces.
This specially concocted vinegar can also be used in rituals to hex another or to encourage them to leave you alone. Place a paper with an enemy's name written on it inside the bottle and hide the bottle in a secure but private place.
It may also be blended with other hexing materials to increase potency of the spell work.