If you want be sure your housekeeper is doing a through job when cleaning the washroom you can turn out the light and shine a black-light around the toilet. The black light bulbs use long wave, ultraviolet light to illuminate substances practically invisible under ordinary light. The uric acid in urine glows brightly under black-light and can identify a superficial cleaning of the toilet, toilet bowl, or area around the toilets including the walls and floor. uric acid is the final oxidation (breakdown) product of purine metabolism and is excreted in urine.
You can also use a black-light to find urine spots from cats or dogs that are hard to find and are the cause odor issues due to the fact you cant find the stains once they have dried etc. I have found this useful as my pets have aged and have had accidents during the day that I have not been aware of etc.
