Now this might be true in some parts of the world where people wash their dishes by holding them under a stream of hot, running water (and then stick them in the dishwasher!)1 but I cannot, in my wildest imaginings, think of anyway it can be true in a developing country, where the vast majority of people wash their dishes by hand, and many, many of them lack running water in their homes, so having to transport the water by the (heavy) bucketload. I know that modern dishwashers have become pretty efficient, but I still don't see how they can use less than 3 cups of water -- which would 10x less than we use to wash dishes by hand, in the sink -- to get a load of dishes clean. In fact, the best figures I can find claim that a high-efficiency dishwasher, in its "eco" mode, uses 12 litres of water. A sink is full enough for a stack of dishes with 5 or 6 litres.
I lack any way at all to measure the energy efficiency: our hot water is heated by the solar panel on the roof, so our energy expenditure on water heating is almost nil. Really, really hard to get 50% more efficient than that!
I won't even begin to get into comparing the embedded energy costs of constructing, plumbing, transporting, and eventually disposing of, a dishwasher! After all, to be completely fair I'd have to figure out the embedded energy cost of our sink and solar panels...
The ad closed with the tagline "so do your bit for the environment." By buying a dishwasher?
Sponsored by Reckitt Benckiser South Africa, makers/distributors of Finish dishwashing products, the ad is part of their campaign to "increase the penetration of dishwashers in the country by an additional 100 000 units by the end of 2007" gratuitously aided by some addle-witted plunk-heads at theCentral Energy Fund -- a state-owned energy company -- who didn't think to question RB's self-serving lies.
After my third viewing of this disingenuous piece of crap, I could stand the deception no longer. Booted the trusty 'puter, and fired off a complaint to the Advertising Standards Authority.
Well, the weeks ticked by. I have not seen the ad lately, so assume that the ad-campaign has come to an end. Lo', yesterday, arrives an email from the ASA, freighted with a PDF:
"A hypothetical reasonable person, on seeing the commercial, would understand that it is a fact that dishwashers use 50% less energy and 10 times less water than washing dishes by hand. The documentation at hand, however, does not specifically confirm this, and specifically indicates that 'study need to be continued to verify these preliminary learning.'Victory is Ours! A small one, but victory nonetheless.
"Based on the above, the [ASA] Directorate is not satisfied that the claims that 'dishwashers use 50% less energy and 10 times less water than washing dishes by hand' is substantiated. The commercial is therefore in contravention of [the advertising Code]....
"the respondent is required to... withdraw the claim.. with immediate effect... from every medium in which they appear"
 I've seen it with my own eyes, but being a polite guest in their house, refrained from my usual sort of reaction.