What's the best way to prevent swimmer's ear?

Swimmer's ear is an infection that's often treated with prescription eardrops. To prevent swimmer's ear:

• Keep ears dry. Encourage your child to wear earplugs while swimming. After swimming, dry your child's ears by wiping the outer ears gently with a soft towel or use a hair dryer. Put the hair dryer on the lowest setting and hold it at least a foot (about 30 centimeters) away from the ear.
• At-home preventive treatment. If your child doesn't have punctured eardrums, use homemade preventive eardrops before and after swimming. A mixture of 1 part white vinegar to 1 part rubbing alcohol might help promote drying and prevent the growth of bacteria and fungi that can cause swimmer's ear. Pour 1 teaspoon (about 5 milliliters) of the solution into each ear and let it drain back out. Similar over-the-counter solutions might be available at your drugstore.
• Avoid putting foreign objects in your child's ear. Don't use cotton swabs in your child's ears, which can pack material deeper into the ear canal, irritate the thin skin inside the ear or break the skin.