Kitt,
Thanks for your suggestion, however, I've done exactly this and it didn't touch it. I'm reasonably sure the "poop" is from Geese and has calcified. I even tried vinegar thinking it might help to solubilize the goose poop. It didn't. I don't want to use anything more acidic or basic for fear of disolving the stucco. So, I'm stuck for the moment.
compact man