Try Mr. Clean Magic Eraser. Worth a shot. I've seen it take some stuff off that I didn't think was possible.
Which appears to have come from the same site you found that picture on. Did you try those yet?Bleach, Simple Green, toothpaste and alcohol-based mouthwash have been known to work with various rates of success, and can be tried first before attacking the spores with a scraper. For removing spores off of cars oil, vinegar, car wax and tree sap remover have all worked for people that tested them
Yeah. None of that stuff works. I did a lot of research on this a while ago. I trust the professional house wash forums. There just is no good answer. Magic Eraser works a little bit, but none of the pros want to touch the stuff because the labor is still astronomical.Also this:
Which appears to have come from the same site you found that picture on. Did you try those yet?