To clean Swiffer dusters, which I really like, simply swish the dirty duster in a sinkful of sudsy, warm water, rinse, and roll in a paper towel to blot out excess moisture. Reattach to handle, fluff, and allow to air dry. These are expensive refills to buy and you can use each one many times this way!
Again, another tip about how to re-use or re-invent the pads that are used for Swiffer mops. My questions is, are Swiffers really that great when any old thing will work in place of the manufacturer's pads? I've seen tips for using old nylons, old rags or towels, dryer sheets, you name it. Try an old-fashioned dust mop if you want to save some money! No replacement parts necessary!
I too have started washing the hand held swiffer duster (not the floor swiffer) I just put a little Dawn detergent on it and swish it in about an inch of warm water in my sink. It is amazing the dirt/dust that comes off. I then place it on a towel separate all the "white" layers so the duster is flat, then fold the towel over it, gentle roll up and wring dry. Unfold and it is pretty much dry and ready to use again! I decided to do this till I have used up what I have (which this way will take awhile since the one I am using now has been washed about 4-5 times and is still good as new) and then try my hand at making some like I have seen on Pinterest from leftover flannel. As far as this verses old nylons, old rags or towels, dryer sheets, I think it all is preference. Those things wouldn't work though on the swiffer duster that I believe Melissa is talking about but for the floor swiffer.