Firstly the ingredients:
-A shredded bar of soap (I am the only one I've read of who uses Octagon. Fels Naptha, Zote or Ivory bars are the others that I've read of but never found in the stores around Va.), 1 cup of Borax & 1 cup of Washing Soda. NOT BAKING SODA. Washing Soda is hard to find, I used to get mine at the Commissary or Kroger. I have no idea where I'll go now, still looking. You can get it off of Amazon, I've seen the links. I've also found that grating soap falls in nicely under one of those productive watching tv or listening to something on the computer activities. Children like to help too & cats will hang around. Something about the smell of fresh soap makes cats crazy.
-Add your shredded bar of soap to 12 cups of water & stir until the soap melts.
-Add your Soda & Borax & stir them until also dissolved. Please do be cautious, this is the concentrated part & while I'm not, some people may be sensitive to the smell. Also it's pretty hot.
-Pour 8 cups of hot water into a bucket w/ a lid. For this I use my tea kettle & any bucket should work. The Costco ones are the perfect size. It doesn't have a by volume rating, only that the original powder was 28 lbs. A lid is a must w/ children around.
-Add the soap mixture to the hot water & stir.
-Add 2 gallons + 12 cups of hot water & stir yet again. Please be careful, this is heavy & hot. If there are small children around you'll probably want to move it all to another room like the garage or outside before your bucket gets too full & heavy.
Let it sit for 24 hours & voila! You've got about 200 loads for pennies on the dollar.
Some quirks; I can't vouch for 200 loads exactly; I did keep a talley of diapers for one bucket & it washed 86 loads of just the diapers, so 150 is proabably closer. My bucket just says 200. You'll want to use 1/2 a cup per load & while it is gross initially; (it looks like snot or egg drop soup) your clothes will get CLEAN. Don't be dismayed at lack of sudsing action during your agitate cycle, it is a low sudsing soap. If you want it to smell pretty add some tea tree or lavendar oil. I've never used the stuff, so I can't say for sure how much to use. For a whitener I recommend the sun. It just can't be beat.
For a cost breakdown, go here: http://www.thefamilyhomestead.com/laundrysoap.htm, she's got it to .71 a batch.
The above recipe is for a double batch. 1 bar of Octagon is around .84, so it works out pretty good for us. Enjoy!