Product review (5 stars): No more residue at all!
I had the worst problem with my dishes coming out with a milky white substance on them, no matter what rinse agent I used.  Our water in our city is very hard.  I didn't want a water softener installed and a friend told me about this little gadget.  I bought it feeling skeptical but my husband installed it (easy) and after the first or second wash, my dishes starting coming out virtually residue free!  I am thrilled with it!