I’m curious about this too. I also bought the coffee sock to try and reduce waste. I took the advice of the fellow at the shop to keep it in water between use and boil it once per week. My water consumption was way up and I still couldn’t keep it clean. The first few cups were fantastic but eventually the flavour of old oils comes through and I haven’t found a way to get rid of it.
Now I just use paper that gets tossed into the compost. Maybe this is more environmentally friendly?