That looks awesome. I'm curious, given the tiny volume of sanitizer liquid left, why is there a need to keep it free of O2? 1 mL of water, even with 10ppm DO, will contribute a negligible amount of overall oxygen. On the other hand, lining the can with an oxygen scavenging solution could help with some of the oxygen introduced at packaging. When you get your test procedure down, perhaps you could test it both ways?