Guiafenesin will keep the ears clear, and analgesic drops and ibuprofen or tylenol will do the rest. I have well-nigh constant ear infections, and I've been mostly avoiding antibiotics for several years now; I don't want to become resistant. The trick with going the no-antibiotic route is that the person should still see a doctor if the pain doesn't begin to improve in 3 days, or if there is a high fever present. I would discuss this approach with your pediatrician; you can't do it without the help of a doctor in the US, because the pain drops are a prescription drug. Some won't trust parents to carefully monitor the improvement, and think that you have drops to mask the pain, that the infection could do serious damage to the hearing before you checked back in again.
You can also, as previously mentioned, get an antibiotic ahead of time, if your doctor will prescribe it just in case. If the ped. will prescribe over the phone, but just not in advance, get the number for your local Walgreen's Rx and keep it with you.
That way the ped. can call the Rx into Walgreen's, and they can transfer the scrip to the branch in Lake Buena Vista for filling. Most insurances that use Walgreen's allow any branch to fill the scrip, and if not, amoxicillin is relatively inexpensive in any case.
Drops that will dry up external water in the ear are available OTC. These are usually a good idea for a child that spends a lot of time in swimming pools, as they help to prevent swimmer's ear.