ya the bbl can be done, but you gotta buy plugs for that caliber. Not sure what a PT 92 is off hand, but im limited to doing handguns this go around due to thier size.
http://www.shootersolutions.com/barrelplugs.html
Also if you do wanna come down thats cool. But i cant promise good results obviously, as the process is science based by nature.
We need to bead blast your parts, and degrease them thoroughly before the park process. Make sure the parts are nice and clean before they come down.
At the moment i am shooting for parkerizing next weekend.
edit- just saw your thread on the pt92, way cool. I would do all the parts, frame included if i was you. If you jsut park some of the parts chances are they will have a different shade of black than the original finish. Parkerizing by nature seems to have variations in color (in my micro amount of experience lol), just as a heads up. Also, make sure you detail strip it before you bring it down, each part has to be done separately.