Not against Ice Climbers, if Nana's around. <3
Not if the floor is broken and in the way, and not if the ..... spinny-thing (what's it called?) is in the way (altho it won't matter if D3's going the right way or if the chaingrab can be delayed until its spinny time runs out, and of course the grabee will have to have hit it beforehand... but w/e).
Does D3's Dthrow CG work on all characters? (or just most
)
That's all pretty weak, but it's enough that I'm unconvinced. I'm by no means an expert, but it seems there's at least reasonable cause for doubt.