hey i'm gonna try that!
robert~i use Trader Joes brand and we have hard water.
P.S. - Over the past half hour or so this AM I did some WWW searching. Trader Joe is new in my area (I live in the Bronx), and I didn't feel like going to Larchmont or Union Sq. to look, although I think I might pay a visit some time. Unfortunately their own WWW site doesn't provide info about most individual products, so I did an Ask.com search for trader joe dish soap.
Some amusing returns. Seems there were a lot of negative comments (worst, or at least worst-mannered: "sucked ass"), but a positive recommend'n from New York City, where the water is "soft", which was suggestive. More definitive were returns related to use as insecticide, which do indicate that Trader Joe dish soap is actual soap soap. That would confirm my suspicion that you're getting away without a dishwasher full of suds just by having "hard" enough water that that amount of soap simply doesn't work.
I put "hard" and "soft" in quotes because the only truly hard water is ice.