Haha, no; the water is only a conductive path for ions to flow. The 'materials' in water can accelerate or slow down the process. Same situation with soil/grime. The salt accelerates the process.
I have a degree in Corrosion Technology so we'll assume I'm correct. I don't mean that in a 'cocky' way, it's just there is so much misinformation about corrosion/rust out there because few people specialize in the field so I try to help clear some of it up.