Excellent
Works really well.
I had a fiddle and made a few improvements;
-Grouped the C channels and send them all to a master bus. Put a limiter on this to bring the sound out a little. Of course, this master bus could be used for any extra effects you want to apply to the overall sound of the vocoded source
-Removed the sample voice, and modified the track to have a Line-In device so that it works as a real time vocoder.
The original idea is great and really shows what is possible with Renoise. Great stuff!
EDIT; Here you go… Linky