Washing clothing has always been a huge aspect of human hygiene from before the classical era, to the medieval era, to even today in places where electricity isn't available. How do they do it you ask? A good old pair of hands and a wash tub, or a river.

The notion that "tribal mechanics aren't a big part of the game" is pretty moot now, especially with the popularity of adding in the medieval and early-industrial VFE settings, added on top of how much Tribal factions have grown function wise in the past three years (Royalty, etc). Anyone starting in the tribal (or no tech tribal) phase usually ends up spending some manner of years within it, during which they experience dozens of raids before ever being able to do anything much of use with their tainted clothes.

Suggestion: Add the billed (or unbilled?) labor "clothes washing" available to pawns with the cleaning job enabled. This will be accomplished by a pawn taking tainted clothing to the already existent water tub or shallow water and doing work to clean it, one item at a time, pretty slowly (whatever the time cost of an item is in the washer times 2)

This keeps washing machines viable and will keep people using them as they do loads 5 at a time automatically, faster, yet doesn't bar tribal/early industrial from doing some common sense work with a little bit of elbow grease.