Ben & Geoff,
Thanks for making the Maytag newsletter available here.
Something caught my eye in the story. The bit about housewives using soap in automatic washers in hard water, resulting in a soap scum deposit inside the machines. The Maytag testing lab "discovered" that a "pound of glacial acetic acid" would remove the deposit.
That's a bit alarming. For one thing, most people just can't get glacial acetic acid except from a chemical warehouse or laboratory. For another, when I worked in a chemistry lab, I always decanted glacial acetic acid in a fume hood. It's like super concentrated vinegar, and the fumes are not nice to breathe in. A pound of that stuff is about a pint... and being a concentrated acid, it should be added slowly to a tub full of water, not the other way round. So I very much doubt it was a practical household remedy for soap scum deposits.
Of course, there was a simpler solution... add some STPP to the tub before adding the soap. But I don't think STPP came into widespread use until much later.