So, loading the dishwasher and the little “gimme salt” light is on. As I dutifully pour in the lovely fat grains of dishwasher salt I got to wondering what the salt was for. Why, for example, isn’t it all washed out? Why don’t the dishes taste of salt (or, for that matter, of rinse aid)?
So, a quick google and we have the answer: water softening. Not directly, as I’d pondered, but rather to ‘charge up’ the inbuilt ion-exchange unit (which strips out the ‘hard’ bits of water by magic means that my schoolboy chemistry can only just follow. If there are pictures).
More interesting stuff than you’d ever think possible on dishwashers at Wikipedia.
Best of all though is the link to the engineer who found a way to clean his toaster in the dishwasher. Respect.