To actually clean the joints out, you need something that will get in there with some mechanical washing action, that will actually flush the gunk out. My recommendation is that you stop by your local Radio Shack store and buy a can of Flux Remover spray. The can will come with a nice little tube attachment that concentrates the spray and lets you direct it right into the joint.
Since you're looking to clean out a BM42 which is all metalic, you don't have to worry about the solvents in the spray damaging the materials of the knife. If you have other knives with fancy inserts, you'll need to be more careful.
I suggest stepping outside to do this. These solvent sprays often have a very heavy solvent odor. There's no reason to stink up the house (not to mention the health concerns about filling the house up with these vapors).
Flux remover spray contains solvents that evaporate quickly and completely leaving the joints of you knife clean and dry, ready for Militec-1 or any other lubricant.
Speaking of which, our great US Coast Guard recently switched to Militec-1 for all of their balisongs, well... firearms actually. But if they had balisongs, I'll bet they'd use Militec-1 on them too.
Finally, electronics supply houses such as Radio Shack often sell another similar product often called "Tuner Cleaner Spray" (most of you are to young to remember this, but back in the old days TV sets had a big knob that you turned to change the channel (yes, you had to get out of your chair to do this) and the mechanism behind that knob would get dirty and affect the quality of your reception. The solution was to clean that tuner mechanism off with this spray. So some reason, they still sell the stuff today. Why? I'll tell you why... I don't know... It's a tradition.) This stuff has a lubricant in it that doesn't evaporate. The lubricant used is not appropriate for this application. So, we don't want that. So, avoid spray cleaners that also brag of containing a lubricant.