Chapter 29 of TROTG has been out for only hours, and I was already alerted to a continuity error (Thomas had indeed promised his crew to provide a financial advisor for them once their prize monies would be be paid out) and a painful screw-up: lye soap on the tissue of a vagina or a penis would have effectually prevented any fun during the wedding night. Ouch indeed!
The financial advisor was easily organised, and the cleansing is now done with soapwort (Saponaria officinalis) infusion, saponin in other words. The corrected chapter 29 was posted and should be up shortly. I hope that poor Mirabel can forgive me!
Thanks to Vlad and jantrevor for the warning!