Slightly off-topic, but one often overlooked bike cleaning tool is the plain corrugated cardboard shipping box from your internet chain cleaning machine order. Tear off a paperback book sized piece and its edge will fit perfectly between the gears of your cassette. Work your way around. The torn edge works particularly well compared to the factory edge. Repeat as needed. Works with the wheel/chain on or off the bike.

Put more cardboard under your work to protect the floor.