Hi Jules,
I was recently seen by a Gynae and she advised for very dry skin in the vulva area the best moisturiser is a simple ointment that is very thick, she suggested Epaderm or similar. I have been washing with Hydramol and moisturising on an off with it too, then using the thick stuff at bedtime.
She advised me to stop the Yes products, they are ok for use in the area if there are no challenges but once the dryness is there something less foamy is better