you got source material on your timeline with several empty audio tracks that just get in the way. You don't want to waste hours with unlinking, deleting, reattaching hundreds of clips manually.
> just import a sufficiently long audiotrack... any quality or format will do. (a long mp3 is ok) > place it in the timeline > move it over the tracks that you want to clean so that it "covers" all the unwanted audio - once you move it again, the audio "beneath" it is gone > repeat for the audio on each unwanted track unitl everything is tidy and clean. That's it. You can erase the unwanted tracks from hundreds audio clips in seconds. Once you're done, you can delete the long audio track that you used as an eraser.
This question has been asked and answered on the Adobe Forums, ( https://forums.adobe.com/message/8936038#8936038 ) but the answer did not work for me... at least it did not do what I expected. somehow just seemed to "mute" the unwanted audio but the clips till keeps the same amount of audio tracks.
I just posted this quick workaround here, in case someone might need it.