Cleaning Pebble Dash

[swsgm30]

Just had a brick wall cleaned by a guy using what must smelled like a chlorine based solution which seems to have been quite successful.While on-site he suggested he could also clean an area of white pebble dash with the same stuff. I was a bit reluctant as we've not long had new upvc windows and I don't know what the effect would be on the Mastic fillings. The Pebble dash looks a bit tatty due to road dirt and is not in too bad condition - just needs a tidy up .. any thoughts/suggestions ?

Thanks in anticipation

[welsh brickie]

i wouldnt recommend it,it could cause more problems.