[Blackadder]

Hi all. I've done a couple of roof moss removals lately but by hand scrubbing, which gets the job done but is time consuming  and tiresome, I've been asked by two neighbours to do theirs and they are fairly substantial sizes.....can someone advise me on the best method for speed and safety (and don't say 'call a professional') 
Ps, I did try the other forum but no one seems to respond on there.

[Rob@Blast off]

Pressure wash it