LOL hey orange juice and milk are another example of things that are good but not together :) Or whiskey and cigars ... but oh wait, those are actually good together and the more the better
Did you doc give you any topical steroids for the contact dermatitis? If that's what it is, even mild topical steroids (desonide is a popular one for sensitive areas) should be able to bring it down quickly. Weird that you would get the irritation only in the vulva area, but maybe nitroglycerin or its metabolites are excreted in urine?
If it makes you feel any better (probably not), our docs here don't really know much about applying the various fissure ointments either. It's like black magic, and everyone has their own way of doing it. I was a fan of the "baby oral syringe in the butt" approach but some others swear by the "finger in the bunghole" method In fact if you look at the medical literature, even it doesn't have any real agreement on the single best way. If you're getting it around the anal opening and maybe ever so slightly inside, you should be doing it right.