Erik the Pink submitted this idea :
I use paper filters for coffee, but I use a plastic reusable filter in my tea
pot. Over time this filter gets black, blocked up and crusty. Soaking it in
neat bleach cleans it up a treat. I'm still alive after having done this for
decades.

I'm not worried that bleach might poison me, rather I wondered if it
might attack the filter material. Its that crusty, just touching the
inside of the filer covers my fingers with thick, very sticky coffee
residue.