Haier top-load washing machine strip-down clean in Mueang Chiang Mai: pulsator black all over

What I did

1. Test-ran the machine before dismantling
2. Removed the pulsator, inner tub and filter assembly to wash separately
3. Scrubbed the black deposits off the back of the pulsator and the rust off the outside of the tub
4. Cleaned the bottom of the outer tub and the filter assembly
5. Reassembled, levelled and ran a test cycle

Result

The pulsator is back to its original blue, the stainless steel tub is shiny, and the bottom of the outer tub and the filter assembly are clean.