To get a perfectly clean cassette, there is really only one efficient way. And that is to remove it and clean each individual sprocket. You can rub a cloth between sprockets, but it dosn’t work that well in my experience. So if you’ve ever had that burning question of “How can I remove a cassette”. Hopefully we can help.
Firstly, we need to remove the wheel out of the frame, so shift down into the smallest sprocket, just to make it easier to remove the wheel/put it back in.
Once that is done, undo both the QR skewer, and the brake caliper leaver, to allow the wheel to come through the brake blocks. Remove the QR skewer from the wheel.
Put the lock-ring remover tool into axle. Put the chain-whip around a suitable sprocket (around 22t.) facing so that if you were to push downwards, the cassette will not freewheel and move. This will be trying to turn the cassette clockwise if you were looking at it.
Put the spanner on the lock-ring, going anti-clockwise as you were looking at it. Push down on both the chain-whip, and the spanner. This should loosen the lock-ring.
Remove the lock-ring from the cassette. This will allow you to take off each sprocket individually apart from the block of a few gears towards the bigger sprockets.
Please note, that there is a wide notch on each of the sprockets. Each of these match up with a wide slot on the freehub. (12:00 position)
Note that the wide notch is at around the 11:00-12:00 position on this. Of course, it will move around.
To put the lock-ring back on, make sure that all the sprockets are on the freehub properly. Then insert it into the grooves.
Tighten the lock-ring back up using the spanner, no need for a chain-whip on the step. Tighten in the clockwise rotation. Do not over tighten. Make sure that all the rings have no wobble on them, before putting your QR skewer back in, and inserting your wheel back into the frame.