From my experience it does both, although salt build up removal does require a little more aggressive approach with repeated applications over a shorter period of time. I use it in a pump up spray container on my brakes after launch, motor flush ( about 2 minutes) leaving the product in the engine. Spray boat and trailer down, leaving the product on without rinsing. Does not remove wax or any polishing product. Leaving quite a nice finish. I believe it is worth the money if only for the time saving in clean up, but on removal of thermostat have observed quite clean water jackets (block). Don't know much about white vinegar but find the Salt Away with its dispenser attachment uses approx .5 %. product to water. Anyway, no I am not a distributor Just knowing after over forty years around boats on salt water and a past commercial fisherman, the damage salt water can do. The old saying "an ounce of prevention is worth a pound of cure" works for me. Cheers, trapper