IMO, each tank (system) will clog any sock you select at different intervals, no tank has the same type of organisms producing the same types of waste; ultimately what works for one system might not work for another ...your change interval will depend on how quickly or slowly your systems production of waste will clog them. On newer setups socks can be clogged very quickly at first as all the particulars roaming freely are removed but, once that's done they can last weeks without needing to be replaced. That is until you start adding inhabits and they start producing waste that will start to clog them.
...for years I've said it's ok to wash your socks in the washing machine, hot water, with a cup of bleach, after the first wash I turn the socks inside out and wash them again with just hot water, if your pairanoid go a third time (just hot water) and let them air dry. Once they have dried they are absolutely safe to use.
Note: the washing machine is a bit brutal on the plastic ring and sooner or later the sock will need to be replaced.