Overall, it's a sound idea to use spare resources (ie. staff) for commercial benefits - but the majority of hotel owners will definitely not be interested. Housekeeping is a considerable expense for hoteliers and most focus on maintaining or driving down the 'cost per room' for cleaning. For the potential profit involved (once split between workers and hotels) this would be a nightmare. Liability, staffing, booking, insurance, workers health and safety, just to begin with, would make this extremely hard. Not to mention, hotels have dynamic inventory shifts and resource needs change hourly, as the needed 'full check-out service' and 'daily clean' needs shift with occupancy.

However, we're looking for a great developer for a related project and want to discuss collaborating on something. Feel free to contact me via hoteliyo.com/contact . Cheers