Lye Soap
I know there is at least two of us here in the forum that are soap makers, myself included.
In soap making terms, "lye soap" means soap made with lard, "Castile" is made with 100% olive oil, or it should be! All soap is made with lye. After the reaction of the lye with the fats, oils, butters, or combination of the three, no lye should exists (after cure) and by the same token not too much fat, or no fat should remain either.
What is the purpose of the soap that you want to make? Bath, Facial, Laundry? If I know what you want to clean with the soap, I may be able to help with a simple cold process formula you can do yourself! Maybe just a 1 lb batch?
Hit me back if you want help, or more info.
Stan