As I said I’m using the one from the pound shop can’t really see much if any difference , they all remove dirt and algae ,plus the fine black spots that are seen on close inspection .. algae spores ?
i find muc off , or any of the "pink" coloured cleaners, While they seem to remove dirt and alge etc quite well they leave a white chalky deposit on the van, which then has to be wiped down. may try the car stuff next.
stu