If it can be impossible to offer the metrics and timetables, then this expectations are unrealistic as well as the strategy is likely to fail. It makes it so much easier for you and the guests and stops certain people from leering!
Keep in mind this is simillar to your car insurance, public liability appears with no law suits discounts. Stairs may be a badly lit, or rugs may be damaged or frayed, ultimately ensuring in trips and therefore falls.
None of those concerns are appealing, however by ensuring that the pump is cleaned out after every use will stay clear of a great deal of of these problems. The cup also has a low volume sign so that you don't run out of paint in the midst of a task.