At least for the Smith and Son ballast, it has not been washed. Once it gets wet, the nice dusty look on it goes away once the dust is washed away. If you add glue to it you've sealed that non-dusty look.
I experimented with just about every ballast out there before I proceeded. They all changed to some degree or another or I never could get the color I wanted.
In the end, I used Smith and Son white ballast and colored it with latex paint and that gave it the color I like. It also washed and sealed it. Then I ballasted with white glue and water with minimal color change. Then I weathered along the tracks some with an air brush.
I could have colored and sealed any of the ballast out there, I just had a bunch of Smith and Son on hand.
