1 Cp Peroxide
1 Teaspoon Baking Soda
1 drop liquid hand soap, or some people say dawn or any dishwashing liquid.
Here's a thread that talks about it.
http://www.yorkietalk.com/forums/yor...er-recipe.html
We used this back in the old days, but many detergents can leave things in the carpet, that attract dirt to the spot. I still think Nature's Miracle is the best and leaves no ring of demarcation.