My suggestion is, if the airlines can afford, it should employ a toilet cum cabin cleaner on every flight especially the long ones. At the moment, most airlines depend on the cabin crew to keep the toilets and cabin clean. This is not very effective as the crew have other duties like preparation and serving of meals, drinks etc. Plus it is not hygienic for the crew who are food handlers to attend to the toilets and clean the cabin.
Many years ago, SIA had musicians and singers on some flights to serenade the passengers while they were having their meals. It also had the jackpot machines girls on the long Hawaii flights. Therefore, why not have a cleaner on the flight?