In the case of “Swimmers Ear” wet canals rapidly cause infection which can cause light to severe earache followed by itchy ears. A great product for those of us who swim a lot or who have moist or get moist, sweaty ear canals from non-vented custom molds, is a product we have in Australia called “AquaEar”. It consists of Isopropyl Alcohol which rapidly combines with the moisture and evaporates it, and Acetic Acid to kill the infection.
Aquaear Ear Drops helps prevent and helps treat swimmer’s ear the painful ear infection that often occurs when water is trapped in the ear canal after swimming, bathing, surfing or diving. Aquaear dries up moisture and retards the growth of bacteria.
I wash my ears after swimming and once a week when I don’t swim with soap and rinse with warm water. I dry the outer canal with a tissue and apply 6 drops of Aquaear for 60 seconds per ear. After 5 mins my canals are perfectly dry and happy. No more itching! I love this product. 
Google “Swimmers Ear drops” to find the name of the similar product in your region…Ear Clear, Vorgee, Swim-eze etc…