Laundry Detergent Project

I am in the midst of a laundry detergent project.
I am trying several different soaps in the recipe to see which detergent I like the best and which one is the most economical to make. I had never thought to make my own detergent before, but with five kids living in the country, I have so much laundry to do that I thought perhaps I could economize on detergent costs if I made my own.
My laundry detergent project has tested using Fels Naptha detergent, ivory soap, and homemade soap. So far I cannot detect a noticeable difference using any of the bar soaps, so my recommendation is to use which ever is the cheapest. I do like my clothes to have a nice (but not overpowering) smell, so if I went with the ivory soap, I would probably add a bit of lavendar essential oil to the deteregent (just note that if you add a fragrance, you also add cost). But a detergent without fragrance is very desirable to many.
You would have a fragrance free laundry detergent with the ivory bar or with your own homemade soap. I would be sure to modify my homemade soap intended for the laundry just a tad. I would strive for a bar that does not have any margin in it (usually I have 5% superfatting for a mild, gentle soap). I think it helps not to have the extra oil in the soap. Again, I have not done a scientific experiment to prove this, but I personally would try to have a bar without margin. If you need help in making your own soap go check out my website at How to Make Soap
I am still working on this project and am sharing the laundry detergents with others to get feedback, so I will post the results as they come in.