@donasmrs-- I think either type will work well. I personally us a mullein ear oil which also contains eucalyptus and tea tree oil. And the carrier oil is almond oil instead of olive oil. This formula has been working great for me. I put a drop in each ear after swimming and whenever I develop an ear ache. Mullein ear oil has definitely been preventing ear infections for me.
Of course, you should always read the ingredients carefully and avoid products with ingredients that you are allergic to. My sister, for example, is allergic to tea tree oil so she cannot use this product. It's a good idea to try a few drops of the ear oil on the arm to make sure that there are no allergic ingredients. You should do this if the product contains an ingredient that you have never used before.