When your hair dries it is going to feel oily but this is good because all of those oils are seeping into your pores and healing your skin. Allow your hair to dry with the oils in them at least overnight. When you get up the next morning, take a shower and wash your hair as you normally would. You will notice that your skin feels incredible and your head no longer itches. If the symptoms come back, repeat. You can't overdose yourself on essential oils. You can use them as often as you like!
By the way, if you are interested in DoTerra's products, would like more information or to place an order you are welcome to visit my website or to contact me personally to place a wholesale order! DoTerra's Essential Oils are #1 Internationally because they are purely organic. Many of their oils can even be ingested which is virtually unheard of with other companies! I believe in their products and use them every day and I would recommend them to everyone!