You'll need (for approx 480 loads):
Arm & Hammer Washing Soda--$3-$4 (NOT Baking soda)
this can be found in grocery stores, the top two at Walmart
Grate the bar of Zote. Add 3 cups of Borax and 3 cups of Baking Soda. Place in food processor to chop Zote into finer pieces. (The other two help make the Zote not so waxy, so it doesn't stick to your blades.)
Viola! You are now done. Place it in a sealable container. Use 1 tablespoon for small and medium loads and 2 tablespoons for large loads. Also, the dry detergent works best washing in warm or hot water (the soap may not dissolve all the way in cold), so if you wash in cold a lot you might try the liquid.
You will still have enough Washing Soda and Borax to do another batch, you will just need to get another bar of Zote.
(I took pictures, but am having trouble getting the camera to upload, so when I fix that I'll add them.)