I have two show cockers. If your dog is stratching her ears I’d take her to the vet and get her ears cultured. That way you’ll know exactly what is going on in there, if it’s allergy, or bacteria, and exactly what medication you’ll need to get the ears cleared up. After that regular flushing using one of the recipes on here, or the link Polly posted, or an ear wash recommended by your vet can help to keep her ears in good shape.