borax is different than boric acid. They both come from Boron. It looks like boric acid is better for insects, but borax for some other things like cleaning. A lot of overlap though
https://homescopes.com/garden/borax-vs-boric-acid/
I have some bulk boric acid I use to get rid of bugs sometimes. Mixing up a batch, saturating cotton ball etc takes time, lately I’m more likely to grab a can of big spray, or sprinkle Amdro where I see ants and bugs.
Yes, it’s derived from the acid.
I was anxious to use the home-made detergent recipe because it’s so economical. But it doesn’t work very well.