I agree with you about any possible unnecessary use of anti biotics. But an ear infection is a really acute thing and painful, and could possibly cause damage or spread, and a short course of amoxycillin could have that sorted in 5 days.
There are herbal alternatives, but not all herbs which are helpful for humans would suit dogs.
Herbs are just not as quickly effective as antibiotics for something like this though.
A herbal or holistic veterinarian would be able to advise, if it's possible to .
consult one?
Echinacea Angustifolia (root) is usually okay for dogs, but that would depend, as it is definitely contra-indicated if there's any auto-immune problem, or allergy to plants in the Daisy family.
Myrrh tincture and garlic are also powerful anti-microbials...BUT may be UNSAFE for dogs (you would need to check that carefully with a herbal vet!!) Myrrh and garlic (raw) are also bitter and harsh, and therefore unpalatable for dogs and could even make them vomit, unless given in capsule form (hidden in food.)
My honest advice would be to go for a short antibiotic course in this circumstance, and your dog will feel very much better very quickly.
If you do that, then giving a probiotic also such as live yogurt is a good idea.