He is talking some sense.When washing your car you should never use a circular motion as it will swirl the paint,but also don't use a sponge.A wash mitt used in straight lines following the body work and always start at the top and work your way down.
As for hand car washes I would not go there free.Do you think care about how your car looks,after doing say 10 cars with the same sponge and probably same bucket of water,it will be like running sandpaper across your paintwork.