I use the illuminating magnifier from Lens Pen. Works well, much faster than any other method. I use the lens pen and a bit of air. If needed I do a wet clean but since I got my sensor replaced on the M9, which I can tell is a different type of sensor, not many problems. The dust doesn't seem to stick to it as much as the old one. The magnifier though, really, really made life much easier. I have a Leitz scope I could use beside me here but the magnifier is better and easier.