@David James I agree that vinegar gets hot more quickly than distilled water when mixed with NaOH. But if you let either type of lye solution cool to a specific temperature before soaping, then that initial heat reaction becomes irrelevant in terms of time to trace. Once the solution has cooled, I never found that a vinegar-NaOH solution moved any faster than a distilled-water-NaOH solution.
I don't think anyone is claiming that vinegar makes for a harder or longer-lasting soap. Vinegar does cause the soap to firm up sooner in the mold, so it can be unmolded sooner and more cleanly. For me, this eliminates the need for sodium lactate, which often gave me chalky spots in my soap.
Which brings me to the point that all salts are not created equal when it comes to making soap. I personally have a great preference for how vinegar behaves in soap, as opposed to table salt or sodium lactate.
But that's me, and you are free to have different preferences on that point.
Sorry, I didn't see this post before responding to
@David James, and now I have more clarity on why he said what he did.
You will not lower the pH of your soap by adding vinegar. Vinegar will only "use up" some of the NaOH to convert into sodium acetate. Due to less NaOH available to convert the oils into soap, you will end up with a larger superfat - unless you adjust the lye to compensate for that. But again, no effect on pH.
Regarding the rest of the debate as to Yoni soap, I'd encourage you to use the search function to read all the prior posts about this. I don't think I can add anything to that.