Hi Jeanne,
Thanks for your question.
I would first recommend that you watch our video “How to Properly Clean a Dog’s Ear”.
We don’t currently have one for cats but you can apply the same principles.
I would certainly caution you against using peroxide as this can be quite irritating to the skin in the ear. I would avoid the olive oil as well since it would tend to stay down in the ear canal due to its viscosity and thickness. The best thing to use is a regular ear cleanser from your veterinarian or local pet supply store. These products have an astringent quality, which helps dry out the ear. This is an important feature to prevent infection since it will help prevent the ear canal from remaining damp.
For a great demonstration, you could ask one of the registered veterinary technicians at your local veterinary clinic to show you how to perform it. They are a great resource for this type of advice.
I hope this helps. Good luck!
Dr. Clayton Greenway