1. Screw cleaning scrubby onto the domed end of the tray.
2. Check that the tube has cooled down entirely to room temperature.
3. Pour in a bit of water and optionally some soap.
4. Use the brush end of the tray to scrub it out.
5. If needed, make sure to only twist the tray/scrubby clockwise (from user's point of view).. this will keep the scrubby from unscrewing from the tray while inside the tube!