Each batch yields approximately 32 ounces (between 32-64 loads)
1 bar soap (Ivory, Fels-Naptha or whatever you like)
1 cup of borax
1 cup of washing soda (You can use baking soda instead, but it does not work quite as well.)
Grate the bar of soap with a cheese grater. (Or, for an easy and fun for the kids way of doing this, try heating it in the microwave and then crumbling it with your fingers.) Mix in the borax and soda and thoroughly stir for 5 minutes. Store in an air-tight container. Use 1-2 Tablespoons per load depending on the size of your load and how soiled the clothes are.