We did ours last year. It was a right pain getting all the green 'moss' off first. I looked like the Jolly Green Giant when we'd finished brushing it off.
Well, not giant, I'm not that big, but you know what I mean
Need to jet wash patio this week too ...joy of joys !! Taking dad to hospital tomorrow for consultant reviews in diabetes and oncology so enforced day off for me here....probably get it done Thursday weather permitting !!