calkat, Here's a recipe that said you can use any type of soap.
Homemade Laundry Soap:
1/3 bar Fels Naptha or other type of soap (If you are using Ivory, grate it and use the whole bar.)
1/2 cup washing soda (not to be confused with baking soda)
1/2 cup Borax powder
You will also need a small bucket (2 gallons). Grate the soap and put it in a sauce pan. Add 6 cups of water and heat it until the soap melts. Add the washing soda and the Borax and stir until it is dissolved. Remove from heat. Pour 4 cups hot water into the bucket. Now add your soap mixture and stir. Add 1 gallon plus 6 cups of water and stir. Let the soap sit for about 24 hours and it will gel. You use 1/4 to 1/2 cup per load.
imspecl (Budget Living Group forum)
This recipe is for a septic tank if you have one.
HOMEMADE LIQUID LAUNDRY DETERGENT
7 c. water
1 c. regular Dawn or Joy (1/2 cup ultra Dawn)liquid dishwashing soap
1 c. Borax
1 c. Baking Soda (I use this instead of washing soda and doesn't make a difference)
In a cleaned out liquid laundry detergent tub (or similar), combine the dish soap and water. Don't shake, but swirl around to combine. In another container (I use a cleaned out butter bowl), combine the borax and baking soda. For every large load, measure using the cap on the liquid soap or it measures out to about 1/2-3/4 cup of the liquid stuff. I swirl it around in the jug before each use to make sure it is still combined well. I pour into the wash and then add about 1/4 cup of the mixture of borax/baking soda.
For septic systems, bleach is really bad so for the whites I use about 1 cup of vinegar to help whiten the load. Then wash away! Hope this helps anyone with septic systems! The main thing is to not let phosphates in your system (which Dawn does not have in it). I posted a while back about a homemade laundry detergent powder using flaked soap, but I have a septic system and after reading up on septic systems on the internet, they really don't like flaked soap that well-LOL. Lots of expensive damage can be done to the soap stopping it up. So, I did some more research and I've been using this for about the last month and it works great on the clothes (even gets out stains better than the powdered kind). From: CountryCook_IA