I agree with Ron. I have an ileostomy, and Hollister M9 drops work the best for me. You can buy them cheaper on eBay, if you don't have insurance.
I've tried 3% hydrogen peroxide, but the bubbles it produces makes my pouch blow up like a balloon, and mouthwash just made the output smell like minty poo, which is just wrong!
Hope that helps!
Cecilia