> "...So how should I do it? ..."
I already said I have no idea how you should scale up your process to make large quantities of liquid soap. I gave you the general idea of what you need to do, but that's the extent of my knowledge.
> "...The castile soap production process is very different from soap production with surfactants..."
Some definitions --
Soap is a surfactant (surface active agent). Any surfactant that is able to clean is called a detergent. Soap is a surfactant that cleans, so it iis also a detergent.
There are also non-soap surfactants. Non-soap surfactants that are able to clean are detergents, just like soap. Non-soap detergents are typically called synthetic detergents (syndet), however, to distinguish them from soap.
You don't want to use the word "soap" when you're really talking about a syndet cleanser.
All detergents are surfactants. Not all surfactants are detergents. These words apply to soap and to non-soap cleansers.