Bushwalk Australia

Does anyone have any suggestions on how to remove some very fine (and sticky) beach sand from a tent fly?

I have a Hilleberg Kaitum 2 and i've been meaning to clean it for weeks now, it's half pitched downstairs and I really don't know how to go about getting all of this sand off. I had a go at it in the front yard and that was a disaster, the front yard here isn't the best place to clean a tent.

A good hose down is what it really needs, but as you are from Adelaide, that is a precious commodity to waste on such an exercise unless the runoff can do some good on the garden or grass if you still have any. Have you tried brushing or vacuuming then a wipe down with a damp cloth?