I respectfully disagree with you cduluck as you have a good amount of experiance in the facts of leather and its surface coatings.
Problem is i am not talking about scrubbing the seats with hot water to soften the surface , but cold water and basic wiping of the surface which removes the dirt on them. it works great and will not harm anything .
Also i did my car 3 years ago and they are in better shape than most peoples with 350 000 km on a car.