Be careful what you wish for. High tech high-efficiency washing machines may use less water, but consumers are discovering that they can get by using less detergent too, according to analysts. That explains a long-term decline in US detergent sales, according to John Owen, an analyst at Mintel Group. They fell 6.4% from 2009 to 2013, and are expected to drop an additional 5.9% in the five years through 2018, according to Mintel estimates. Things will get even worse as more consumers turn to ...