OMg now you got me goin.. But it all is very simple if you ask me and i'm about 99% sure it has to work.. If you look at such an air difuser darrel points to, it is one such as this. This works with the force of nature, the venturi creates a pressure drop or an up speed in flow whatever (not that important to me right now) at the left hand side, this makes air sucked into from the atmosphere instead of water being sprayed out. Now this venturi is about going from 16mm to 10mm back to 19 mm where the air is sucked in. There is a cross shaped septum placed at the 16 mm section in front of the venturi, this will also reduce and scater the water flow, probably also to create some vortex and make the water go wild behind it. The air which is sucked in behind the venturi gets scatered into little tiny bubbles and difused even more along the way. That's all it takes to difuse air with a venturi, as long as water flows it works and doesn't spill a drop of water. An educated guess, if you push through presurized co2 instead of air, it doesn't need to be that much say for example 0.5 bar / 7 psi or even less it will get scatered and difused as well. My theory says because i think it's only logical, that if there is a venturi close enough in front of an inline difuser, then already (Ceramicaly) difused co2 gets difused even more.