1/3 bar Fels Naptha or other type of soap
1/2 up washing soda
1/2 cut borax powder
Grate the soap and put it in a sauce pan. Add 6 cups 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. Now add 1 gallon plus six cups of water and stir. Let the soap sit for about 24 hours and it will gel. Use 1/2 cup per load.
Optional: If you want your soap to have some sort of scent you can scent with 1/2 to 1 oz of essential oil or fragrance oil of your choice.