Well, I do not think you are really going to get really effective results using one with a canister filter pump.

They are really under powered.
This is the trade off using a mazzei.

Now, there is a solution and it's along the lines you want........and it'll match the goal you have, but the trade off will be less mist control, but that might okay for you.

Aqua Medic Reducing Tee - 21 mm x Airline Tube (Aquarium > CO2 Systems/Access. > CO2 Accessories )

Note, there's no suction draw, this is not a venturi.
You need good check valves.

However, there is NO head pressure drop at all.
These are what I added to the lower flow systems using canister filters.

They work fairly well, the bubbles exiting are not many and not that large.
However, you do not get the ultra fine mist that comes out of the mazzei.
The high pressure is what creates the energy to shed the gas to bits to form the froth.

Regards,
Tom Barr