I usually buy at least 2 pairs of socks in the same design. That way if 1 of either pair is lost or stained, I will still end up with 1 wearable pair. And when I talk about getting some socks to dust with, I am not talking about buying new ones to start with.
Start collecting those that you or your children have:
2) lost a side
3) stained too much to be worn without embarrassment
When you dust the conventional way, with a feather duster, the dust will fly up into the air and land else where. If you missed sweeping a speck away, there it stays. And you wouldn't want that happening if you have children at home who are sensitive to dust particles.
So, go find that 1 sided sock, moisten it up a bit and slip it over your hand and start wiping away the dust with it. Once it is stained, turn it around on your hand so that you have the other side of the surface to clean with.
If you have more areas to dust, don't wash that dirty sock yet! Turn it inside out and...
...you will have 2 more surfaces from the inside to work with.
All sides used? Now you can wash. Great job! You have just save time, save water and reduced waste.