I thought this article (link below) was interesting because I recently treated Sirocco for an ear with black gunk in it and was told just this month that another Mythicbells kitty who’s been in her new home for quite a while was also diagnosed with the same problem. Bad kitty mommy in my case. I did not suspect ear mites, and Sirocco was not favoring her ear, so I was not ‘mollyonthespot’ about getting her looked at. I’d cleaned the ear several times — it was just the one ear. You are likely to see a little gunk in cats’ ears, but it’s unusual for them to really get dirty unless something isn’t quite right. I should have realized that. In any case I did get the ear checked. It was a yeast infection. I treated it and she’s fine. But she was ‘Grease Head’ for 10 days. These things happen.
This article explains how the bacterial and yeast medications are often combined to cover both bases: