My mother-in-law listens to your program through Sarnia, Ontario CHOK, and she told me that you had recently discussed a product to use for cleaning asphalt shingles. She could not remember the information. Would you mind dropping me a line with this info? I just registered today. Your site/topics look really useful.
Answer:
Vinigar just mopped on will do a good job for you and you may have to do it a few times; particularly if the area to be cleaned doesn't have full air circulation around it.