Many years ago in an ATC sub-centre, far far away, the contracted cleaners would hoover the ops-room during the latter stages of the evening traffic peak. The old hoover was very noisy and would sometimes mask the RTF. One of the ATCOs MOR'd the hoover and, as a result, we got a brand-new, almost silent, hoover, (called Henry), and the cleaning was switched to the lunch-time 'slack period'.
The CAA allegedly, used this example in presentations about what the MOR scheme was about.