I've found a fantastic ( an cheap ) method to keep your kilt clean without water! It is a simple rubber dog-hair removal brush.

here is a link to one at walmart:

http://www.walmart.com/catalog/produ...uct_id=3635649

lay your kilt out flat, set the pleats correctly, and brush the kilt from top down, in short, quick strokes. The rubberized bristles remove hair and most large particles of dust, dirt and other such things. It works very well, and only costs a few dollars. So far I have not seen any damage from using this on my kilts.

Hope this helps!