Don't know if you can use this on cats but one friend of mine has a cat and I know she uses the wash for her dogs so she must use it for the cat also.
For the dogs I've always used the Blue Wash... it was made up by a vet so after being told about it I tried it and was amazed at the results. I don't like putting anything strong on any dog so this was the perfect thing. My dog caught ear mites only once. I used the wash for about a week and it was done. Now I use it once a month just to make sure the ears are always clean and to avoid any sort of ear trouble.
You can google Blue Ear Wash and the recipe comes up. Very simple.