When I was researching recipes on making the laundry soap, I sort of combined and tweaked several to make my version. The batch I made lasted me one year and just the other day I made my second batch for the coming year.
Here is my recipe, in case you are interested.
1 55-oz. box Washing Soda
1 4-lb. box Baking Soda
4 to 5 lbs. OxyClean
Scent crystals, optional
I learned it is easier to grate the soap if it has been microwaved. I do this in my garage with all the doors open because it really has a strong smell. Yes, I learned this the hard way when I made my first batch. It's a good thing hubby has that extra microwave sitting out there in the garage for me to use. I cut the soap bar into quarters and place two quarters on a paper plate. In my microwave it takes a little under two minutes and it will puff up and feel lighter in weight. Let the microwaved soap cool well. Once it is cool, you grate it. I grate the soap in my food processor which has a shredding blade. Oh my, did that work great and so quick.
Next I mixed all the ingredients together. I guess on the quantity of OxyClean because I usually buy an 11-lb. container of it. So really, the recipe is no exact science and a little variation is okay. I wear a dust mask while mixing everything because some of this stuff is very powdery.
Next I put the mix into containers. I use a small scoop, which is about two to three tablespoons in size and I use just one scoop per load of laundry. If a load is heavily soiled I may add a bit extra or just toss in some extra OxyClean. I figured that the cost to make this was about $20 to $22. And that lasts me for the year. By the way, I buy all my ingredients from Walmart, except for the OxyClean, which I buy at Sams Club.