Product review (4 stars): If you have an older Whirlpool Duet Front Loader order directly from Pure Products International
A total of Three units were sent to me from the Green Giraffe, none had a template, owners manual or warranty card. Tried all kinds of configurations, Y connector from hot/cold outlet and y-connector from pure was unit to washer hot/cold inlet, removed filter screens from washer inlets, nada. No bubbles were generated in the display window in the pure wash unit. Called Greentech directly. The tech was very friendly but simply said they had no solution if what I tried didn't work. Sorry but nothing they can do.  Called Pure Products International after seeing that their customers  with a similar washer had success. They took pity on me and sent me a replacement part (had to pay shipping, no big deal). I had to swap out the Venturi plastic tubing unit, easily done, just keep track of the bracket locations since not all the brackets are the same. Connected the cold water outlet to the unit, y-connector from the unit to the hot and cold inlets of the washer, Viola! Bobbles, bubbles, bubbles! It worked. I guess Pure Products sell thousands of these pure wash units and they knew what to do after I texted them a photo of the inside of the purewash unit. I found that it takes a few washing cycles to clear out your washer and also, several washes of your clothes. Clothes are clean and soft. No hot water needed, in fact not even connected to the hot water outlet. Thanks to Nicola and Brenda at Pure Products!