I have everything set up (I think) but OpenVDB volumes that I import do not get denoised. I changed the default cube to a volume domain and loaded a VDB file in (Disney cloud). I tried both the viewport denoise and the final render denoise (F12), but neither worked.
Here is the viewport view and settings:
Here are the settings for the final render:
And here are the results after choosing the denoised volume image from the passes menu:
Jason