I apologize if this has been addressed before, but I've read posts on borax until my eyes have crossed and didn't see an answer. I would like to add borax to make HP bar soap, mostly for it's possible water softening ability. I've seen varying amounts for CP soap mentioned but not HP. Anyone have a suggestion for a good amount PPO, or a percentage of oils to use? I would be adding it dissolved in liquid after the cook. Should I try the same amount as for CP? And if so, how much would that be? I would like to try it for water softening, not necessarily for mechanic's soap or any heavy duty cleansing. I have seen old recipes (that I can't remember where) that used pretty small amounts of borax, so I just wanted advice so as not to use too much.