So here's how it went:
I decided to try the recipe from Building It On Pennies.
The boiling part.
All mixed together.
The final result.
The soap didn't "gel-up" like the recipe suggested, but she also said that it would work regardless. So, I gave it a try, and used it on two loads so far, and I'm very pleased with it.
Thanks to my awesome readers for the suggestion to try it out!