I've been using this since July and share the recipe with anyone who wants to be frugal and clean!! It works really well and you can use it in He machines. It has a nice clean scent but if you prefer you can experiment with essential oils to give it a different scent. I like it like it is.
In a 5 gallon bucket half full of warm water, dissolve the Arm & Hammer Super Washing Soda and the 20 Mule Team Borax powder.
In a medium sized sauce pan, grate the bar of Fels-Naptha soap with a vegetable grater-I used the 4 sided one-and add 4 cups of hot water. Bring to a boil over medium heat, stirring frequently until dissolved. Pour into the 5 gallon bucket with the dissolved powders and water in it. Stir until well blended. Add enough water to raise the level to about an inch from the top of the bucket. Stir gently to mix together. Cover with lid or if no lid is available aluminum foil works just fine, and leave overnight.
The soap will be thick and gelatinous. Break it up and stir or agitate until fairly smooth and most clumps are dissolved. I think the easiest way is to just roll up your sleeves and reach in with both hands and begin squeezing and stirring! Now you will put it into your individual containers. Saving your old milk jugs or large juice containers works really well. Using a funnel put half of the soap base into the container and then finish filling with water. Now you will have made 10 gallons of soap!