Adobe Audition (roundtrip)
Most free "denoisers" fail because they smear chroma and luma together. You want a plugin that attacks Chroma noise aggressively (because it looks fake) and Luma noise gently (because a little grain looks cinematic).
If you want, I can: 1) recommend specific plugins based on budget, or 2) provide step-by-step settings for a named plugin (iZotope RX or Neat Video).
