no, because you would have to let the molten salt react with the sacrificial metal, introducing a lot of complicated impurities into your salt bath that may influence your reactor in numerous ways.
...unless the sacrificial material is a component of the salt anyway, like Beryllium.
ORNL proposed to have a Beryllium rod in contact with the fuel salt. It isn't needed to prevent corrosion of Hastelloy N in clean fuel salt, but it was intended to scavenge the fission product Tellurium, which was found to otherwise cause corrosion.
