Traditionally used for protection from disease and magickal attack. Four Thieves Vinegar is believed to strengthen you and weaken your enemies while driving them away.
Uses vary, but we will give you one: Write your enemy's name 9 times with Dragon's Blood ink on parchment. Place parchment in a bottle. Throw with a strong hand into a moving body of water. This is said to drive your enemy away -- far, far away.