Nights, stays and the two revenue lines
Booked nights are the available nights times the occupancy rate. Divide those nights by the average stay and you have the number of stays, which is what determines the cleanings. A three-night average stay means 73 cleanings in 219 booked nights, and each of them is charged to the guest and paid to the cleaner.
The cleaning fee is therefore a revenue line and a cost line at the same time. Where the fee exceeds the cost it contributes a margin; where it does not, the nightly rate has to absorb the difference, and a long-average-stay listing feels that far less than one that turns over every weekend.