I tested the stone, doesnt work.
I tested the upgraded box of hurt, doesnt work.
I tested the base box of hurt, also doesnt work.
I havent tested the Frag Grenade but I dont think I need to, given the other 3 dont work.
I have played it on Heresy, and as the penace said elite or specialist enemies, I hit 4 in a row without missing an grenade once, yet still not a single bit of progress.
I thought since the upgraded box has grenades that those count as “misses” but apparently not when you cant even do it with the base version.