You could also extend the not-washing period if you buy more clothes. The more you have, the longer until you run out of clothes to wear.
A few time ago I realized, due to different materials or black ink, they degrade in different ways, so I have a few shades of black to choose from.
But still don't care :).
That way, you're obviously always wearing mismatched socks, and it becomes an obviously deliberate (if eccentric) fashion choice instead of a repeated sartorial goof-up.
Also, you get to wear socks that are more fun.
Socks didn't use to be a fashion statement but they sort of are now. Mixed socks. Because, y'know, I don't care. I just don't care. I'm just me.
LOL, so corny. I'm not sure anymore that I'll be able to pull of mixed socks.
Not to mention being more power and water efficient.