04 June 2008
I have tested several Ilford films (in 35mm format) and the "film base + fog" has ranged from and optical density (OD) of 0.25 to 0.36. Your measured OD of 0.33 does not seem too high.
If you want to reduce the FB+F density as much as possible I recommend using fresh fix, and at lease 5 minutes in HCA. Both of these processes will strip as much of the "anti-halation" dyes as possible.
As for the "airport control", as long as the film is not placed in your "checked bags" you should be ok. Most films, except really fast films, will not see fogging until after 4 to 5 passes through the x-ray machine.