the water would creep up the walls of the container while the gas wouldn't rise to the top
While I agree that this setup wouldn't work in space, that's not why. Absent external forces, particles maintain velocity forever. So if you were to pour water into this container and stabilize it, it would simply sit there. It wouldn't creep up the sides. Also, the gas would rise to the top because density still exists in space, and density is what causes gasses to move upwards in an aqueous solution. However, this upward force on the water would likely cause significant disruption in the otherwise stagnant water which would likely render the entire process pointless. To force it to work, you would need a constant (relatively) downward force strong enough to keep water pooled at the bottom but weak enough to allow gasses to rise up out of the container. My solution to this would be a slow spinning centrifuge. The centrifugal force would mimic the force of gravity which should allow this design to be kept and used in space.
However, upon reflecting upon Stocking's diagram, it appears that that method should be more effective not to mention more space conservative. It's not nearly as complex as it appears at first glance, it's really just performing the same action in a way that pumps can be used to supply the force that would otherwise need to be supplied by gravity. Absent the pressure regulator, it's almost exactly the same design.
