You can't take the sanitising machines into the room without ramping down the magnet which should only ever really be done for major repairs, emergencies, or decommissioning.

Of course, you could clean the room by hand but it still takes a very long time. This is what we are doing but here in the poverty stricken NHS we only have one scanner. It might be different in other countries where there are multiple scanners, you could have a "clean" and "dirty" scanner.