I have scrubbed another series of walls with the power brush and sugar soap.
I want to go back in time and throw sugar soap on the series of people over at least the last 10 years who never cleaned this place, because the smells were *distressing*. And look, yeah, it's not that common of a thing to clean walls above head height, but still. I couldn't even see what was causing the smells. (Don't start me on the nicotine staining either. You'd think a hallway wouldn't be so bad for it, but you'd be wrong. I still haven't figured out how to remove it from around the light bulb fitting - as in, the bit the bulb goes into, because apparently the glass surround didn't make any difference there.)
And also to throw used cleaning cloths at whoever installed the hallway cupboard such that it has a lip above it that can accumulate dust, that's extremely hard to get to with anything and impossible to see from the ground so I can guess why it had such thick dust. (And also to ask why the fuck they even bothered, because you need a ladder to access the cupboard anyway, and it barely fits a box fan. Can't see why there was an issue with having ceiling there.)