Which ear cleaner are you currently using? Could you ask your vet about an alternative one?
I have a boy that suffers with his ears. My vet recently recommended
TrizULTRA + Keto from Dermapet - it's fantastic and so much more effective at getting to the root of the problem as it contains a topical antifungal ingredient. My vet has a dog with ear problems too so she really understands what works.
Although it's more effective it seems less 'acidic' and so is kinder for repeat washings/applications
HTH :)