Is "not working" based on irrefutable proof?
We cannot assume it is not working because someone said so. Therefore, evidences should be provided to be able to confirm that it is in fact, an issue.
OCIO has nothing to do with denoising. It is applied after denoising, at the end of the chain, in post. Assuming the exported render is a linearly encoded EXR as anything else makes post non-viable, besides log-encoded integer output.
For more information,
visit the color management section of this page for export settings, post workflow, octane preferences, and so forth.