It costs pennies to the dollar over commercial synthetics, uses no petroleum byproducts, and is sustainable. It won't cause detergent buildup on clothes, cloth diapers, or your machine.
Who can benefit from this? Your wallet, those with sensitive skin or respiratory allergies, and of course, the groundwater.
Step 1: Ingredients
If you can't find Washing Soda and/or Borax at your local Mart, ask them to get it for you, or you can also find it at various online places like "soaps gone buy".
Note, this is not the same thing as Sodium Bicarbonate, which is Baking Powder. Sodium Carbonate, sold, as "Super Washing Soda" by Arm and Hammer, or as "Washing Soda" by other brands, is used in everything from swimming pools to wet-process photography, and can be mined in its raw form, from the ground. It's a natural Earth substance, but caustic, which is why it does a good job. So don't leave it on your skin or get it in your eyes.
I use Kirk's Castile simply because it's cheap (a buck and change per longlasting bar), easily available, contains no animal products and is never tested on animals, is made from Coconut oil, contains no strong synthetic fragrances to set off my allergies, and is honest, pure soap without synthetic detergents (which are all petroleum byproducts, did you know that?)
I find Ivory too soft, and because so much air is whipped in, you get less actual soap per bar, and I couldn't verify the ingredients to my liking.
But if you want a fragrance, you can pick up a bar of Dr. Bronner's soap and have your pick of lemon, rose, lavender, and more. Costs about $4 per bar last I checked, but still much, much cheaper than storebought detergent.
If you make your own soap, even better.
Step 2: Grate the Soap
Step 3: Mix It Together
Step 4: Find a Container
Step 5: A Little Goes a Long Way
If you find clothes are stiff when you line dry them, you are using too much. Cut the amount in half, and add a little vinegar to your final rinse.
You may also have "detergent buildup" from using commercial brands, and may need to "strip" all your laundry of that buildup. (pretty good racket, I think, because then everyone "needs" fabric softener!)
Using this mix will help remove buildup over time, but if you have a bad case of buildup, washing with nothing or with only vinegar, until you see no more suds coming from clothes, is one way to tackle that problem.
Step 6: Enjoy the Results
Ok, they aren't snowy white, but we need to get over whiteness as a goal anyway, because bleach destroys cloth and the environment. But they are clean and soft, no stiffness from detergent.
Step 7: And If You Want Whiter Whites...
(the ones that irritate skin and shorten the life of clothes?) so your whites may yellow a bit, especially if you use an electric dryer, because the sun will whiten your whites naturally.
But if it's winter, or you can't use a line, etc... there is a time-tested method for whitening that is nontoxic and trusted: bluing.
And you can also use it safely to make fun " Pacific ocean" baths to end a cranky day for the kids on a happy note, and make other neat things from it.
Simplicity never felt better.