Erm...a few issues:
1. Why would sea salt as opposed to just regular salt make a major difference? Sea salt has maybe 1% extra mineral impurities compared to just regular salt, there's basically no difference.
2. What exactly would salt do to scars?
3. He doesn't seem to be talking about scars, he seems to be talking mostly about acne control.
4. If he has any improvement on his scars at all, it's very likely that he's just experiencing microswelling that he's sustaining on a regular basis. A very hot bath + rubbing your face with a brush would cause an abrasive effect that causes your skin to swell, which results in the appearance that scars are gone. But, in reality, it's temporary. I suppose you could do this everyday for the rest of your life, though, kinda like a make-up thing?
I don't mean to sound like a pessimistic asshole, but if hot salt water + a bit of brushing everyday really fixed acne scars, then these forums wouldn't exist.
There is a difference atleast to me because table salt REALLY irritated my skin and broke me out. And sea salt didn't.