That reservior is to hold a salt brine. Zeolite rocks inside the Miele capture minerals effectively softening the water. To remove these minerals the dishwasher regenerates the rocks by back washing with the salt brine. If you set your Miele to the lowest water hardness level it effectively shuts off the regeneration cycle. I added one dose of thier salt and have had no odor since. Apparently nothing can survive in the salt brine.
Zeolite_man, January 2009