Aluminium and copper won't rust BUT it'll form something not so nice especially the copper like err... "burnt".

You can use very high pressure blower to blow it off, borrow one from car garage shop (if you know them well enough to do so)
Or if you can afford compressed air, it's a nice way to clean electronic stuff.

If you really can't use those above, rinse with water and quickly use hair blower to dry it off (prepare it before-hand), and this is NOT recommended.
If it does form some stains (or "burnt") after sometimes on the aluminium/copper, you can use anti-rust cream to polish it if you really sensitive by the stains.