the bug with the deathbane mod leading to martial items that should have had a insc slot ending without one has been fixed some years ago. today only staves still present this behaviour. so BDS can still drop without insc slot, but crysta not. this is my status
To my knowledge, the bug only made them much more common to drop, but clean drops werent exclusive to deathbane.
Ive bought many cleans from zchest and random drops etc over the years and ppl selling have Several times claimed it was recent drop. So i belive they still drop just extreamly rarely.
100% agree with this. I have personally pulled non staff cleans from zchest when I got max rank a year or so ago. Was purposely looking for examples to prove you can get a "OS looking" gold ball hammer. Never got one but did get a couple examples. I'd have to search screenshots but I recall not keeping them because they were annoyingly core skins that can drop OS clean elsewhere so was nothing special as couldn't be identified as "zchest cleans".

