Why are so many office cleaners on contract? Security issues in many contexts, plus loyalty to organization issues. Once thought that a card reader scam had originated via cleaners at a particular bank branch, since rarely used the card elsewhere.
Also, why clean only at night?
Very different arrangement in the House of Commons; perhaps a model. Office cleaners being career-oriented House of Commons employees, generally cleaning during the day. Didn’t have to be working overtime to get to know, and for them to know.