Robin, moss on a flat surface i think it would remove, I don’t think it would remove the moss in the grooves of a set drive the brushes don’t project deep enough, they would skim across the surface
As for cleaning solution I’ve tried all sorts and most work, I think its the agitation that does the cleaning but this is only on natural stone which to be honest is an easy clean.
The Cimex is really for Indian stone which has ‘brushed-in’ pointing which can be quite fragile.
I wouldn’t buy a Cimex for the sole purpose of exterior cleaning but if you have one already it’s a useful thing to use
Rich do you mean Cimex or have a spelling mistake on my site? They cost about £3k new