To clean my decks, I use a cloth lightly dipped in salt water. To cleanse the deck from reading to reading I put them in order of suit, not necessarily in numerical order. However, I did have a situation a couple of weeks ago where someone abused my lovers card, I was doing a reading and he picked the card up and went balistic over it, slapping it, flicking it, and put a crease in the card. Oooh, I was furious! It seems like I haven't been able to read the deck since (could just be me), I can't seem to get rid of that negative energy. This weekend I am going to buy a replacement and see if it makes a difference.
All in all, I think it's personal preference.