To clean my bolex I use canned air, and an orange wood stick. I remove the door when there's no film loaded, remove the pressure plate, open the gate, and rest the base of the bolex against an edge so that as I spray it the dust leaves the camera. I make sure to spray the area around the gate, and keep an eye out for areas that look like they'd accumulate dust.
Orange wood sticks can be found at Walgreens or CVS; they're really cuticle pushers, but because the wood is particularly soft, they are great for removing the emulsion on the metal above and below the gate (where the pressure plate covers). I take the slanted edge of the stick, and gently scrape the metal. if you see little black pieces of emulsion, you're doing it correctly. I also scrape the inner part of the gate (carefully avoiding the shutter).
There's another little trick I learned for the pressure plate. Spray the plate with canned air to remove dust, then rub the plate against your nose! Then grease lubricates the film! It works.
I used these technique while I was driving across the country with my bolex. I would be in dusty environments all the time: my camera would be hanging out the window, I'd be in the desert, etc. I shot an hour worth of film and there wasn't a single scratch or hair in any of the shots. It's important to keep your camera clean, and these methods seem particularly effective.
