I wouldn't go there since you never know what their wash mits an drying towels are like. We have two sites like you describe near me, but their mits and towels are filthy. They go from one car to another; no washing, no rinsing, no swaping out for a clean one.
I totally get where your coming from...with that being said I've never seen any damage to my paint from them and it's much better than not touching my paint all summer (which is a solid 5-6 months)...too damn hot to wash my truck here...maybe if I woke up at 4 in the morning
I haven't tried one of these rinsless/waterless washes...seems so counter intuitive to just spray something on your car and then used a microfiber to clean it...seems like you would just be wiping grit and dirt all over your paint, but I guess I should give that a shot for summer cleaning?