I've never experimented with Calcium Hypochlorite/Powder.
I read a lot of negative things about it when I was a member in the
old forum.
I wish it worked well though!!! Because S.H. is not as easy to get in Erie, PA.
I have to buy it in 5 gallon jugs from a pool supplier.
I agree with not experimenting on other peoples roofs. This goes with all roofing products.
I tend to stay away from the "New" products until they prove themselves.