I've heard that ocean salt water is around 30,000 ppm and most SWCGs require around 3000 ppm. The generator creates chlorine which is what sanitizes your pool. I don't know about ocean water, but I'm doubting it's possible to sanitize your pool using only salt (at any level).

Using a quality test kit and swcg, how is that not practically maintenance free? It's the lowest amount of maintenance possible.