I use a dog shampoo and conditioner called Buddy Wash made by a company called Cloudstar. As of right now, I don't think you can purchase it in stores, but you can order it online at www.cloudstar.com
They are good sized bottles for the price, especially since chi's are small and don't need a lot when taking a bath. They make a regular formula and a flea formula. And, both formulas have a matching Buddy Spray that smells just like the shampoo/conditioner. I have the lavender and mint scented and Chico's skin and coat are doing wonderfully with it.