The Oozinator does NOT have a separate pressure chamber. I suppose that is why it has a normal fill cap as opposed to one of the Max Infusion or Fast-Fill caps. The Bio-Ooze part requires the canister that holds the Ooze to be used. I can imagine that once the Ooze is used up, the canister can be rinsed and filled with water, instead. However, the bottom assembly cannot be filled on its own; it'd leak if one tried. Pumping the lower pump, air can be felt being pushed out of the nozzle.
That's it for now. I'm going to go take some pics and do some limited testing (even more limited than I thought at first). Currently, I won't be able to do any measurements on the 2nd nozzle since I'm not ready to open up the Ooze canister.

