Hanging clothes in direct sunlight is overkill, and probably reduces their useful life due to the UV. All you need is sufficient moving air. I hang mine under the deck or just on racks indoors.
Sunlight isn't an overkill. It's a great germ killer (You have to be cautious not to leave them out for too long, lest the UV/Heat damages the colours).
You can use a lot of detergent to remove the last bacteria; but household detergents are a big source of water pollution.
Or you could throw your clothes into a geyser [1] :)
> (...) The group put their soiled clothes in a pillowcase and threw it into the geyser’s cone. When it erupted, the clothes were sent flying over a hundred feet into the air. When they collected them, the churning, heated water had indeed cleaned them.
Not sure why everybody assumes fusion powered implies direct sunlight.
Drying clothes in the shade is also powered by the sun, because the air only has "unused" moisture capacity because it was heated at some point. To repeat the cycle forever it will need to cool down and then be heated again.
You can use a lot of detergent to remove the last bacteria; but household detergents are a big source of water pollution.