i had th same question they said to wash it in bleach unscented in the washer machine or you can let it sit in bleach for a day and rinse it the next day. after washing let it air dry you should do this every 3-7 days hope this helps
When I did use the filter socks, I changed them out every other day. I washed them in my front loader washing machine (which does not beat the heck out of the clothes.) I put approximately 1/4 cup of bleach, and put them through the rinse cycle 6 times.