No. Think about water spots. What are they caused by? Not water! It's caused by what is in the water ie solutes eg calcium. If you pour distilled water over the car, it will dry without water marks. Hence why some detailers connect a filter to the hosepipe when rinsing after shampoo.
You need something that will get rid of calcium. Vinegar is supposed to be good for this. Try a 50% solution.
Claying may work but you'll have to resort to polishin if there's any paintwork damage.