I remember blue bags, and driving past the factory in Cumberland (or Westmoreland) where they were manufactured.
Before modern detergents they were put in the rinse water to make whites look white. There was a time when a woman's competence as a house wife (and this mattered) was judged by how white her whites were when swinging on the clothes line.
Inevitably, back then, everything anyone used seem to have several other uses beyond their prime purpose.
My mother got a washing machine very early in the 1950s when I was only 7 or 8, and I have very little memory of washing before then, but I think it was hand done in a sink. We never lived in a house with one of those big built in coppers my DH remembers from his home.
Shall we reboot our cartoons thread again? 😁