You think the Sorceress would notice the smell reek in her scaly skin while the under sun. That's a pretty big deal and I'm surprised it's optional dialogue and not in a cutscene with the Sorceress zapping Moneybags into small pieces of bear meat.
I like to believe that he tricked her into believing that mayonnaise is actually a type of sunscreen. But still, a cutscene would have made that so much better.