Yes, they do work well and they do get better with age; but never ever put downward pressure on it. Shake the old stuff off and LIGHTLY move it over the car.
--I've seen people use them like a broom and press downward as they brush and complain the thing doesn't work because it leaves scratches...Sometimes it's good to follow directions.

Detail spray with a microfiber cloth does work better.

On the dust. I'm betting you park it in a garage with a cement floor that is unpainted. These type of floors throw off a very fine dust that will settle on your paint, especially on newer floors. This dust is very abrasive. Be careful. Using a good quality garage paint (Sam's Warehouse has a good one at a reasonable price--follow the directions).