I'm not going to comment on motor oil because I've never done the research on it's use in firearms.
I'd avoid graphite. It can corrode aluminum. I won't let graphite touch any of my firearms.
I'd rather run a dry rifle than use Militec-1. It does nothing to stop corrosion, and in the military's own testing the dry rifles had less jams and problems than the rifles treated with Militec-1. For those of you who do use it, don't flame me. I am giving my own opinion (which is what he solicited) backed up by facts. If you like it and it works for you, good for you. Feel free to go ahead and recommend it to him, but there's no disputing what I've said here.
You can't go wrong with BreakFree CLP, Mil-comm TW-25B or Eezox.
BreakFree CLP- Tried and true, still used by our armed forces today. Cleans well, lubricates well, and does a great job of protecting against corrosion. However, it's not good for cold climates and it does tend to run everywhere and not stay where it belongs. It also seems to burn off. Also, I've never quite felt right about lubricants that separate and need to be shaken.
Eezox CLP- Not very well known. It protects great, even better than breakfree. Many a salt-fog steel test sheet has come out sparkling when protected with Eezox. Lubricates great, and from some of the ASTN tests I've read, better than BF CLP. Lubrication is pretty much in line with FP-10 (which is probably tops, or close to, in lubrication). Cleaning seems as good as BF CLP, haven't seen any scientific tests on this, but subjectively it seems to do a great job at pulling fouling out of bores, and metal pores. It applies wet, but the cleaner+lubricant carrier dries and leaves behind dry lubrication & protection. Stays put, works great in Cold climates (-40F). Freezing point is -95F. Does not cook-off.
Mil-comm TW25B- Another great lubricant, protects pretty well too. Not quite as good as BreakFree CLP, but close. It's also not a CLP, so you'll have to use the separate MC-2500 cleaner. It stays put and lubricates better than BF CLP, roughly in-line with Eezox (I'd still give the edge to Eezox). Works in cold climates (-40F) pretty well. -40F is not it's freezing point, that's just the temperature at which the test took place. Does not cook-off. For me, the best reason to use this stuff is that it is completely environmentally friendly. It is entirely not toxic and you could eat the stuff if you want. If you are around firearms all day (gunsmith, armorer, etc.), this can be a major bonus as you will probably get tired (as will your body) of inhaling irritating lubricants for long periods of time.
Personally I used BreakFree CLP for many years. I always liked Eezox's protection against corrosion and that it was dry/stayed put, but I was unconvinced as to it's lubrication abilities. I recently found independant ASTN testing on Eezox and found it was one of the top-runners in lubrication ability. So all that was left was how well does it clean. The firearms I have cleaned with it come out great, easily as good as BF CLP. I will do scientific tests on it's cleaning ability at some point in the future. I use Eezox almost exclusively now. I still keep the BF CLP and TW-25B around should special purposes/occations arise.