A mistake I made with Castille, I think, was that I did not blend long enough to a ‘yogurt’ or mayonnaise-like trace. Things were pretty still fluid when I poured the castille. It was still gel after two days of curing. Anywhere that was not properly cleaned up from the castille was terribly and permanently stained (See cutting board picture). Also, the soap is very chalky. You can see in the pictures below how there’s an outer ‘ash’ surface over the castille. I am seeking advice on online forums to see if soap is salvageable, but anything that’s going to permanently stain a cutting board like that hasn’t got great chemistry to begin with.