I guess if the commercial spray holds the dust better than just using plain water, then give it a try. I spray endust right on the rag and it seems to work reasonably well.

Do you have air/heating vents? Have the filter/s and ducts been cleaned lately? I found that this causes a lot of dust to just cycle through the house. Also, I've lived in place that just seem to be the known center of planetary dust production. Old buildings are notorious for this.

You might also want to consider your vacuum as the culprit. Often times the vacuum puts tons of dust right back into the room. I got my machine serviced and it performed much better.

I also noticed that my cloths dryer, which is in the kitchen, contributes a lot of dust. If I could, I'd have it in a room where I could shut the door.

That's all I could come up with. Good luck!

I tried the anti-static de-duster spray for my old Tv a few years back, and noticed 1% difference in dust-return speed. In other words, it didn't work at all as well as I expected.