Along a similar line, does anyone under the age of 50 use Borax [1]? I assume people must have found it useful for laundry at some point in time, but I wouldn't have the foggiest idea how or why to use it.
I also have successfully used Borax solution in cleaning of porous surfaces to eradicate mildew problems in areas that bleach doesn't work to eliminate long term.
I'm a millennial.
Used "Terro Ant Killer II", which is syrup that contains borax and works about as well as the original formula that contained arsenic.
Also a key ingredient in growing crystals, if I remember my children chemistry experiments correctly.
But I had no idea it was (or how it would be used) for laundry.