I use socks. I wash them in the washer with bleach. Last at least a year. Need to replace about every 5 days. I used 2 on my last system at once and have 12 socks total so once a month I washed them.
Would you mind sharing how you have them setup? Do you have a baffle that they overflow into or do you have them directly under the drain? Also what size socks are you using. Thanks!