the salt won't hurt them at all, but they prefer table salt because it is iodized, and they need that for their exoskeletons to grow back quicker adn stronger. But no the salt wont do a thing to them.
EDIT: I also have ghost shrimp and one had eggs, they started out green then they started getting more transparent. i think the mama let them off somewhere b/c now i can't find them but i read that they like the undersides of plants.
HTH