My favorite for keeping my ZDSD, CSP3 and Zen Mystery Amplifier clean (and all my Electronics + Speakers) is the SWIFFER Dusters with the handle. I use the one on the right. I suppose the 360 degree one, might even be better.
http://swiffer.com/en-us/shop-products/dusting#

I prefer this on handle Swiffer over a aerosol keyboard sprayer etc.... . With the Amp off and cooled down....it picks it all up....without pushing it around + Tubes dusted. Tilted and angled in.......it gets every nook and cranny.

My Equipment/Decware is clean an Showroom Stellar!
I'm not a neat knick or anything.  

I have been using one of those for a long time. Now I also use a 1" paint brush to get into all the nooks and crannies that the Swiffer misses. Just makes sure the tubes are cold. The smell of the Swiffer on a hot tube could kill a maggot. Don't ask how I know.