A full hose down won't hurt anything. Since this is a limited engagement you shouldn't have to worry about significant rusting. Just wash it throroughly on the exposed parts, maybe over the top of the engine. The only place I'd probably not be too keen on getting under/behind is the dash since there's lots of instrumentation in there and few metal mechanical parts (so it shouldn't really matter).
As for sand, as with snow, steadiness and smoothness are key. The bike will catch its own grip once it finds sufficient friction on a cleaner surface so in a corner, keep looking and steering where you want to go, making any adjustment that might avoid less than favorable road now in your view.
Dragging knee is for the track, and dragging tail is for the lot. --Kane Friesen
When you're in a car, you're watching a movie; when you're on a bike, you're in the movie. --Robert Pirsig
Identity theft is not Fun