Hi Postmeno3, funnily enough I've just started using Hydromol (externally) for labial dryness, and it's the fourth of four emollients I tried - Doublebase Dayleve, Cetraben and Epaderm all caused stinging and burning (as did vagifem and estriol cream some months ago). Hydromol is the only one so far that doesn't sting and burn (and actually does seem to help, albeit marginally).
I can only assume it's different skin reactions to the different ingredients - none of this menopause stuff makes sense does it? From what I gather emollients are made specifically for things like ezcema and every one I've looked at has stated 'don't use on mucous membranes' - which I assume the vagina might approximate? Perhaps try it not in the bath, but externally, and see what happens.
Sorry you're having to suffer like that, it's hell isn't it? xxx
By the way, I just bought mine over the counter, didn't need a prescription (but it did take me a looooong time to find out that such things existed - GP telling me to try 'moisturisers').
LL