Hi Amal- the recipe as originally written uses a ratio of 1 part lye to 3 parts liquid (i.e., a 25% lye concentration). If you use the amended recipe (see the notes in red in post #8) it's more like a 4:1 ratio (20% lye concentration).
It sounds like you may have missed reading the notes (typed in red) that I added to my original instructions for making this liquid soap recipe in post #8 on page 1 of this thread. Here they are:
[10/13/2016 Edited to add that I now mix my KOH /glycerin differently than the above. I dissolve the KOH in an equal amount of room temp. distilled water and then add the normal/full complement of (room temp.) glycerin to the lye solution. Doing it this this way makes it so much easier/less fussy to dissolve the KOH. Instead of taking 8 to 10 minutes of cooking in boiling glycerin for the KOH to dissolve, it only takes as little as a minute, and no heating is required. Of course, doing it this updated way changes my dilution ratio because I have to account for the extra water I'm adding up front, but, no worries- I've got that figured out: my new dilution ratio is 1 part paste to .62 parts distilled water, instead of 1 part paste to .75 parts distilled water. To see how things proceed when using my revised method of making the paste, see here. ]
No they do not do the same job. The job of a super-fat is to lessen the cleansing power of the soap, making it feel more gentle/ less drying to the skin. The job of the sodium lactate in this recipe is to help the paste to dissolve in a more timely fashion.
You can certainly use it as a body wash if you desire. There really is no difference between using it as a body wash or a hand soap..... it's soap afterall..... it'll get your hands clean as well as the rest you.
It will not lather as well as the typical body washes one can buy at the store, though, because those found in stores have lathering agents added to them such as SLS.
For what it's worth, I personally choose to use my liquid soap for only washing my hands, and my solid/bar soap for washing my whole body in the shower. I like using my bar soap in the shower as opposed to my liquid soap because my bar soap lathers so much better for me in the shower compared to my liquid soap.....and also because it lasts a lot longer- I don't need to use as much of to get the lather I desire for an all-over body soap.
I think you may be a little confused on this point, and I'm sure my having changed the method of dissolving my lye didn't help, but hopefully I can help clear things up:
My original instructions started with a 3:1 glycerin to lye ratio in order to make the paste (no water involved yet). The lye and glycerin were heated together until boiling, and then removed from the heat once dissolved and immediately added to the oils.....
....and then once the paste was made, I took the weight of the paste and multiplied it by .75 to get my needed dilution water amount: i.e., 1 part past to .75 parts water, which is the perfect dilution rate for this recipe as originally written (at least for my likes anyway).
But then sometime in the future I decided to change my method for dissolving the lye. Instead of dissolving 1 part lye into 3 parts boiling glycerin, which is fussy and carries with it a bigger danger factor, I decided to make things easier/quicker and also reduce the danger factor by first dissolving the lye in an equal amount of room-temp water by weight (which takes barely a minute and does not involve any cooking), and then adding in my original '3 parts' amount of glycerin to the solution before combining it all with my oils. This, in effect, changed the lye solution for my paste from 3:1 ratio to more like a 4:1 ratio.
Increasing things to a 4:1 water/glycerin to lye ratio up front in order to make my paste had the effect of changing my dilution rate later on for diluting the paste into soap in order to get the consistency I liked. Since my paste was now more hydrated/soft, I needed to use less dilution water than normal in order to get the same end-consistency I desired. Instead of using 1 part paste to .75 parts water, I now use 1 part paste to the lesser amount of .62 parts water to get that same consistency.
I'm like Shunt- when adding my lye solution to oils, I just gently heat my oils/fats on low until melted and then add my lye solution. No need to heat the oils to 160F. You can if you want to, but that's overkill if you ask me. Mine only get to about 110F to 120F at the most.
IrishLass