I saved filter socks until I had about 20 or more and then did them in the washing machine. I would wash once with bleach or oxyclean, wash again with just water, then rinse.
Then I would wipe down the washing machine tub and do a load of white laundry with bleach and detergent to make sure the tub was clean!
I do a rinse and spin first, to clean out the plumbing, a sanitize run with bleach, then 2 successive rinse and spins - then let the nose let me know if its enough