The present invention provides a water softening device for application in a household appliance comprising a flow-through capacitor for the production of wash amplified water (WAW) from tap water, having less than 5° FH, being suitable for use in said appliance when the device is in operation; the configuration of the device is such that the capacitor can be regenerated, whereby no added substances are used. Said washing machine being suitable for use with low environmental impact detergent products.