I work with gases. The only way to 'flush' the cabinet with helium would be to have an exit port and would take overpressurizing, pushing air out multiple times. Helium atoms are small - they will diffuse out faster than air, so his numbers really don't mean much in that part of the experiment. But it was interesting that all the different speaker designs made very little difference.
The materials analysis of the various types was more interesting. Never heard of using TP! Not surprising results using rockwool, and interesting that adding foam to roxul was not good. I'd like to see him do it with OC703/705.
Keep this youtube bookmarked to share the next time someone here suggests egg cartons!