Because of its mineral complexity and coarse grain size, sel gris can be used both as a cooking salt and a finishing salt. Being much denser than table and kosher salt, there is a lot more salt in an equivalent volume of sel gris.
Because it is a moist salt, it does not suck all the moisture out of food when used as a finishing salt, unlike kosher salt (which is designed to absorb blood and other fluids from meat).