If the "home" position of the valve is closed, and the valve is properly sealed, I can see it working. My question sits with the financials: How much more expensive is this cup compared to the standard plastic beer cup?
There is nasty beer... and there is great beer.
Maybe to some people but me, no way, no how and I've been to Europe and tried stuff there. Every last bit of it has that horrid funky taste that I cannot describe, lol. Being from Kentucky, I do love me some Bourbon though.