What the heck, I decided to clean my Niche Zero after like a year. Took it apart per usual. I use the thing at least twice a day. I make drip in the morning set at like 50, and espresso set at like 8. I RDT for drip, but not espresso. I always use medium roast beans. In fact, I stick with Verve Coffee Street Level as my go to brew for both. I get the stuff sent fresh from Verve like every 5 days, so it is always perfect.
Anyway, the Niche has been performing like a champ this whole time. And, since I lubricated the threads long ago with vegetable grade mineral oil, it has been smooth as silk to adjust, which I do twice a day. So, after taking it apart and inspecting it, I could not be happier. The burrs are perfect. No corrosion or anything else despite RDT. The chamber had minimal residual coffee as expected. So, a quick brush and wipe, lubricate the threads on the ring with a very light coat of mineral oil, and there you go. Good as new.
I suspect the thing never needs to be cleaned frankly. I mean, the inside was just terrific. I only cleaned it just to inspect it. I am one happy Niche Zero owner. Fabulous grinder for my needs.