I make castile soap easily using sodium hydroxide, olive oil and water. Use the soapcalc.net lye calculator to determine how much oil, water, and sodium hydroxide per batch. I have a gas stove, so after I make the soap, I place it into the mold(s) and store in the oven for at least 24 hours, up to 4 days. Then remove from the oven, set on the counter to harden (it is extremely soft at this stage). Once it has reached a firm stage then I can cut the soap into bars. Then I allow them to seriously harden, like rocks. Then I set it aside for 6 months’ dehydration. A person can let it sit for 12 months. The longer it sits, the milder it becomes. So, basically, between 2 to 12 months the soap can be used for any of the above-mentioned uses.