What goes into the pot is no different with a black kettle or the crock pot. Your difference is the heat source. And as with cooking over a campfire vs an electric grill... some are great at controlling the heat source and some are not. It is nice to experience it I am sure. But I also think that my ancestors, if given a choice to use a crockpot or cooking over an open fire they would choose the crockpot for the consistancy and ease. After all they did not have the soap calculators and we would be hard pressed to do without those at this point. Now also consider that they had to produce more soap... more family members to use it... wash day soap etc. What you are trying I have seen, mostly at civil war encampments, or for re-enactments during a festival.
I have never tried the phenol... cheaper to use my tongue
As for the doneness and ready to use in a couple of days.... I will put away a sample of my soap and revisit it in 6 to 12 months to check for scent and color retention. What suprised me most when I went to use one of these bars is how much nicer the soap was! But I can't always wait... just to eager to give someone in my family a gift!
Hope you have fun getting back to your roots, keep us posted on how it is going!