I have no idea if this is possible but I've found scripts that dig into your system to find different things to use in messenger. I was hoping that maybe it could be possible for someone to make a script that would do that for advanced audio options.
My example of a list of options for voice clip sending:
reverb effects, chorusing, flangers, echos and delays, amplitude shifter, stereo/surround shifting, equalizer.

Of course when I say voice clip sending it doesn't mean it has to attach itself to the messenger voice clips button, it could be a whole separate thing, I was just hoping it could be possible to do.

If anyone is willing to try it out, maybe because it's an idea you think you should have thought of or maybe simply because you want a challenge, please PM me on here or let my know by E-MAIL I'll be most glad, I don't need credit for the idea if it is ever to be made and if you really like, stick it up into the script list giving full credit to yourself and whoever may have helped you make it.

I don't think its really possible on the current WLM API

Alright then I guess it was worth a try anyways.
Either way if it is somehow possible and someone knows how please do jump in and don't be shy to step right up.