I recently had someone tell me that they used peppermint oil on their irritated scalp, and when they went to wash it out with shampoo and water it burnt really bad. They asked if this were to happen again if there is anything they should do differently. The answer is YES!
Since essential oils are oil-based, and not water-based, you should always rinse off an essential oil with another kind of oil – like coconut oil, olive oil, etc. Water will send the oil deeper into your skin, causing that burning sensation, especially with hot oils like peppermint. This is also important to remember if you ever get oil in your eyes. Your initial reaction may be to immediately wash your eye with water, but this will only make the sensation worse.