Miele Collection Water-Softening Salt: Many dishwashers have a built-in water softener to optimize cleaning results. To function perfectly, this softening unit requires special salt. Miele Dishwasher Conditioner: Dishwashers are exposed to a lot of food residue including starch and fats. Regular use of Miele dishwashing machine conditioner can actually help extend the life of your machine and ensure great wash performance is maintained. Recommended use: 4 - 5 times a year (circumstantial).