u/spankhelm

Can anyone give me some info about what this weave is /how to tie it? Image is from u/KillaBlaze614 but they haven't been active in a few years it seems.

I hand rinse my pot every time I use it before use which is about every other day. Whenever I open up the chamber there are always weird little crumbly black granules forming on the black spots. About a month ago I scrubbed this thing out real with a soft wire brush to get it clean. What would be forming on those spots? Is it some aluminum reaction or is it just coffium deposits?