What is in her ears? Is it black or dark brown wax stuff in the ears?
Does she have allergy symptoms(itchy skin, licking paws, hives?)
It’s probably allergies/yeast if it’s really itchy, could be a yeast overgrowth.
What food is she on?? Some foods can actually create the yeast overgrowth and allergies. Sometimes just changing to a high quality food can treat this. Even with ear treatments, if you don’t fix the problem causing this, the ear issues and scratching will keep coming back even with vet treatment.
Skouts Honor probiotic ear cleaner is what I use for Rusty to maintain and prevent new yeast overgrowth.
For my other dog, both the Legendary canine and also Skouts Honor probiotic ear wash both work for her, and nothing from the vet worked at all for her and she got a Huge ear hematoma from scratching.
I would first fix the problem causing the itchy ears, if allergies are the problem and yeast too(most dogs with allergies have yeast issues too).
You can start off with cleaning them daily with witch hazel, but if there is an odor to the ear, it might be yeast which is a sign he could have allergies - either environmental or food.