It is important to know what is causing an ear ache, as different causes should be treated differently.
Swimmer's Ear is a fungal infection, and almost any type of fungus is quickly and effectively treated with vinegar.
Mix white vinegar 50/50 with clean water. Drop into ear, and wiggle ear to ensure it goes all the way in.
This provides almost instant results, especially if the infection is caught early. My son woke with Swimmer's Ear one night, and after a quick vinegar treatment and about fifteen minutes for the pain to subside somewhat, went back to sleep and by morning his ear was completely well.
You may mix vinegar with rubbing alcohol instead of water, but the alcohol will sting and is not necessary. The vinegar does a fine job of creating a pH environment that is completely unfriendly to fungus, and the little bit of extra water will run out and not cause further problems as long as you dry your ear carefully.
Side note: Vinegar of various sorts and in various concentrations is wonderful for other fungal infections as well. I rub it on my scalp for dandruff, for instant results. I pour apple cider vinegar in the bath for vaginal yeast infections, for instant relief and quick recovery. For fungus, vinegar works better and faster than any store-bought or prescription remedy. But only for fungus--for bacterial infections, vinegar can actually make the problem worse. So be sure you know what you're dealing with!