My physician advised 1/2 white vinegar and 1/2 rubbing alchohol. Lay on your side put a few drops into an ear canal until it's muffled and let it stand for a full 5 minutes, no cheating. Roll over and do the other ear.
Some navy studies revealed the 5 minute need.
Throwing in a drop or 2 and walking away isn't doing much more than cleaning the hair in your ears.
The treatment will prevent swimers ear and will also help dry out residual water since alchohol will combine with water to carry it out. Much like drygas for you northerners.
As explained by my physician the alchohol will serve to kill off nasty organisims and also provides a drying function.
The vinegar also makes life miserable for critters in there and helps restore the natural acidic condition in the ear.
Swimmers ear is usually not a product of the swimming water. It comes from normally occuring organisims in the ear that multiply out of contol in a wet no acid post dive ear.
The above treatment should be done at the end of every dive (skin, scuba, swim, whatever) day. It can be quite relaxing if done spooning with your S.O.
Pete