Mute all children/Mute all tabs in panel

[noneuclideanmotion]

Again for example, I have a videos panel. It would be great if I could just mute all the videos in that panel, and it would be great if I could mute all the videos in a specific branch of the tree.

I would do this stuff myself, however add-on development and Javascript are way out of the scope of what I can do.