This is my third version of the compositor node setup which includes the "bilateral denoising filter" of KaiKostack. He has an amazing video and the node setup to achieve the effect.
[link]First section blurs the noise of the scene while preserving the texture while the middle darkens and changes the Ambient Occlusion to multiply instead of Add. The last part is a slightly altered node setup where it adds a small amount of distance fog and glare effects to the scene. The last few nodes just darkens and distort the edge of the picture.
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Sta.sh
I've have used the same configuration for the blur, Vignette, and distance fog for some renders and added to or taken away from them as I went along. The actual nodes I use now are placed into 5 groups to make importing easier.
I'm not sure how to upload the blend file though...
Best thing to ever happen to Blender...