People Wearing Clothing Longer Between Laundry Days
Well there was that, and also that most persons didn't own vast wardrobes we see today. Only the very wealthy could afford huge outlays of clothing.
Even well after the invention of the sewing machine, clothing was still rather dear, at least the good stuff, and not everyone could afford store bought clothing. Many women still ran up their own clothing, as well as that of their families, especially if one lived far from town/city. Or, there was of course catalogs such as Sears.
Your average person probably had only several outfits, with perhaps one or two for "Sunday best".
What did people do? Undergarments, lots of undergarments if one could afford them. They were changed more often, as they could be laundered and ironed more easily. There was also various aprons,pinafores, and other coverings that women, children and even men at times work to keep clothing clean. Again these were easier to launder than garments.
Being as all that may, in the 1920's and well beyond there were still persons who only changed undergarments once or twice a week (usually after the weekly "Saturday night bath"). Considering how persons slept in/wore those same undies 24/7, by the end of the week they must have been *ripe* for the laundry.
Bed linen for all but the wealthy wasn't changed daily, or even weekly (if you were lucky). Napkins were often used for a week before being sent to the wash, and so forth.
Because of the automatic washing machine, IMHO Americans tend to generate more laundry simply because wash days are less labour intensive. People today change clothing several times per day,and chuck items worn for only several hours (or less)into the hamper.
Personally cannot imagine a woman like the one pictured in the advert doing her own family wash by hand. Even in the most rural areas of the country it wasn't hard to find "cheap labour", and laundresses or a girl to come in and help with housework was common enough, even for lower middle class housewives.
Real work doing family laundry by hand?
Oh you bet! I took often three days of back breaking work, from the initial soaking til everything was ironed/dried, and put away. Today's modern washing machines and dryers get the job done in about an hour.
A few years ago PBS/BBC ran the first "back in time" reality series, "1900 House". Here a modern British family was sent back in time to live in a restored 1900 Victorian town house. Not merely a quiant exercise, but I mean they "LIVED" as those would have done then.
After the inital charm of twirling arond in long skirts,corsets and what not, the wife/mother faces the daunting task of housework with only what was available to her great-grandmother. Her biggest shock was laundry day. Using nothing more than Lux flakes, a copper, mangle, sad irons, drying racks, tubs and endless buckets of water, she was expected to do the family wash (herself, hubby, and four children). She soon learned, and schooled her family to stop throwing just anything into the hamper. Things were worn until they were "dirty" and or otherwise unfit to be seen in/worn. *LOL*