Airlock half full of water, glycerin, or vodka, and you're fine. The idea of the central tube is that excess CO2 can come out, but it has to push through the water lock... conversely, the outside air cannot get in because of that water lock. The little floaty piece inside is what really does the work in this regard. So just watch for the float to jiggle and a bubble will come out. Repeat ad nauseum.
All you do to load these locks is stuff lock in the bung, the bung in the carboy, the floaty in the lock, fill half way, put the lid on the lock, and you're done.
Secondary: Sangiovese, Honey Nut Brown, some Pilsner/ale kinda thing that just won't quit...
Tar Sands Porter, Special Dark Bitter,Oaky Red ale, Hammer & Tongs Black Ale, Black Draught, Cooper's Bitter, Baron's Pilsner
Super Saazy Saaz Pilsner Saaz (It's a little green, yet)