I have wanted to be able to manually print duplex for sometime but never scratched the itch until today. With a quick Google search and I discovered
Max OS X allows for creating printing presets and so I have created a "Duplex Pass 1" and a "Duplex Pass 2" presets. The only bug is that the "Reverse page orientation" setting (aka checkbox) seems to be independent of the preset so be sure to make sure it is unchecked for pass 1 and checked for pass 2.
HP has a very useful application for manual, duplex printing but it has stopped working since OS X 10.8.4.