Might be a fun experiment if you have enough salt sitting around. Kosher or canning salt. But potatoes don't have so much moisture in them that a salt bake is required. But for the heck of it, I'd bake them buried in the salt. Bake one in salt, another without. See if you can tell the difference.
I've baked potatoes on a bed of salt before. The part of the potato that is in contact with the salt becomes a bit too dry. Just like if you put them directly onto the baking sheet, the part that is in contact with the baking sheet becomes a little too dry. The advantage of using salt is that the potato doesn't flatten at all. Not a big advantage.