We tried Salt Away in 2009 (didn't make it with the car for 2010) on the tow vehicle, push vehicle and the race car.
It's blatant where we missed with the salt away.
I would be interested in the Salt X, not because I'm dissatisfied with the Salt Away, more of a "pepsi Challenge" kind of thing.
I have to agree about the pressure washer, I still use them, as I have to get the big gobs off but a final cleaning with water from a hose (sprinklers are darned handy) for a while work well.