How often should I run the Eco Drum Clean cycle, and how do I use it?

The Eco Drum Clean cycle should be performed once every 40 washes to clean the drum and remove bacteria. To run it, press Power, turn the Cycle Selector to ECO DRUM CLEAN, and press Start/Pause — make sure the drum is empty and do not add any detergent or bleach. The water temperature is fixed at 70°C and cannot be changed, though the display may show 60°C. (Page 35)