Pure water by itself will not remove polish, otherwise every time it rained cars would be stripped of polish
Car polish is often silicone based, and that isn't water soluable, the same will go for the other car polishes.
I'm not even sure is simple detergent and a sponge will make any impact, not on the polish that been
applied anyway.
On most modern cars, when the paintwork is nice and new, the purpose of polish is to give a protective shield, most cars have a laquer applied over top of the paint itself, all the polish in the world won't make it any 'shinier'. once it is clean, it is as shiny as it's ever going to get.
Windows may often have a 'greasy' appearance when they are really dirty, but that's appearance only, they are not, 'greasy' as such, what's on there is water soluable and washes off easily with WFP.
Ian