Oatmeal contains many natural compounds that will soothe and heal the skin. A good soak in a cool oatmeal bath will help relieve the itch and discomfort caused by poison oak. To make an oatmeal bath, grind up a cup of oatmeal in a blender. Wrap the powdered oatmeal in a piece of clean cheesecloth and suspend it under the running water while filling the bath, then soak for about 30 minutes. Alternatively, you can make a smooth paste of the finely ground oatmeal and some clean water. Apply a thin layer to the affected area. Allow to dry and gently rinse off with cold water. Reapply every few hours until the rash abates and you experience relief.