Its been a while since a Salt x thread. A couple of people have claimed in the past on this site its snake oil, others saying they are dubious, others saying its great.
Have a look at this part of their site http://www.salt-x.com.au/Product-Test.html
I have had a bottle for several years and used it a few times on my old motor. Now I have the 99 model 115 Yam I am looking at using it when the motor is warm and leaving a coating as the product says to do. I did a bit of a test today sticking about a teaspoon full of large sea salt rocks (ie all like small gravel) in a glass with some diluted Salt x 50 solution and it dissolved of its own over the course of several hours...I will do the same with water now and see what that does.
Cheers