Question How To Set AudioSource outputAudioMixer parameter at start

Nearly done with my quest to fix amnesiac prefabs at runtime.. ran into a weird one where a bunch of child object audio sources have no mixer routing. The place from which the noise emanates matters since it's not UI stuff.

The general <AudioMixer> is called "SoundtrackAudioMixer" in our project files.
We have a top level <AudioMixerGroup> called "Master", under which there are a bunch of other <AudioMixerGroup>s. The one I want is named "Foley"

How do I get to it? Tried making a public reference up top like so

Code (CSharp):

1.     public AudioSource emitterAudioSource;
2.     public AudioClip emitterFiringSound;
3.     [SerializeField]
4.     public AudioMixerGroup foleyMixer;

And I even went and set the script import defaults to that specific "Foley" <AudioMixerGroup> but I .. suspect that since that new variable and the import default I assigned to it are newer than the prefab in question.. it doesn't count? Ex post facto file management? I am kinda confused about that but it's neither here nor there.

Either way, I'm not seeing a passthrough yet --- the code below DOES pass a clip to the right <AudioSource>, so I am touching the component I want but it won't pass that ouputAudioMixerGroup.

Code (CSharp):

1.             string mixerName = "SoundtrackAudioMixer";
2.             AudioMixer mixer = Resources.Load<AudioMixer>(mixerName);
3.             string foleyName = "Foley";
4.             AudioMixerGroup foley = Resources.Load<AudioMixerGroup>(foleyName);
5.             emitterAudioSource = gameObject.GetComponent<AudioSource>();
6.             emitterAudioSource.clip = emitterFiringSound;
7.             emitterAudioSource.outputAudioMixerGroup = foley;

I saw another thread mentioning

Code (CSharp):

1. Resources.Load("AudioMixer/AudioMixerGroup") as AudioMixerGroup;

Am I just getting the path syntax wrong? Should I be saying "SoundtrackAudioSource/Master/Foley"? What is the deaaaaaalllllllllll.

Thanks!