Yes i used it for my caravan all the time.It was great at getting the green off and caked on bird mess,as where i stored my caravan they would not let you use a cover :

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However i then used a degreasing agent from window cleaning centre in Ipswich and the results were just as good,a lot cheaper (5 ltrs for £15 approx) and diluted lasted me for a full season and many many conservatories a plastic cleans.
I have now moved over to Ecover from gardiners,under recommendation from Jeff1,as i am putting it through my jetwash...the result is even better on conservatories.I did a small one yesterday,a yearly job usually just done with the pole,and the ecover just ate through the algea with no problems...it was visibly working faster than any previous solutions that i had used.
I have noticed now that Ecover do a range of cleaning products in Morrisons,so i might get a cream cleaner from their range to get the dreaded fly poo off the sills in the summer months.