Several years ago we were exceedingly fortunate to have two light-duty people assigned to the Library from our Physical Plant office whilst they were unable to perform their normal duties. They removed books from shelves and dusted both the shelves and the books before re-shelving them. They cleaned and waxed the tile floors in our stack areas.
Before and after we were never cleaner than when we had the extra people. The library staff did not supervise them; they were under the direction of the housekeeper regularly assigned to the Library.
In our Library, the housekeeper is considered to be 'one of the family' and takes her morning break when the librarians and support staff take their morning break (usually at 0830). Therefore, the extra people usually came to morning break as well and were accepted as regulars. We were sorry to lose them when they returned to normal duty.
Perhaps you could get some extra help at your place in this manner.
New Wilmington, PA