Finish Salt. Hard water might leave limescale residues on your dishes and over time can accumulate in the hidden parts of your dishwasher – reducing its efficiency. Finish Salt is specially made for dishwashers to soften water and protect them from the negative effects of hard water. This is recommended over normal table salts which may contain contaminants that can damage your dishwasher. Thanks to its high purity, Finish Salt gives your dishwasher 100% better protection from limescale residues