A few of my all indoor kitties get very dirty ears, sometimes even just ONE ear like that. I just use dry q-tips and clean them out, once a week if necessary. I wouldn't use water in the ears, that could cause a yeast or other infection to grow in there. I've never used a cleaner on my kitties ears, the q-tips alone seem to do the job fine and bother the kitties far less than if I had to squirt something in there.