I change mine out daily so they never get
that dirty. I have 10 of them. Got them from Bulk Reef Supply - cheap there. I turn mine inside out, then when I have 8 dirty ones I chuck them in the washing machine with hot water and 1/2 cup baking soda, cold rinse. Lay them out to air dry. No soap, no bleach. I have yet to bleach mine (they are a year old) as the baking soda keeps them clean looking and smelling fresh.
For those of you using Prime to dechlorinate, Prime isn't strong enough to handle that much bleach (if you can smell the bleach, the Prime can't handle it), and if you dry the socks out completely before you use them the bleach will off-gas anyway. If you're really worried about it use Sodium thiosulphate which is like 1000 times cheaper and works 10 times better.
