I've thought about using a bicycle CO2 inflator with a 16g cartridge. You'd have to experiment to see whether a 16g cartridge is appropriate for the tyre volume. I've tried a number of inflators on my bike and found that the screw-on ones are much easier to use than the press-on ones. With the press-on inflators, if you don't get a perfect seal on the stem, the CO2 escapes in an instant and you've wasted a cartridge. Some inflators have a variable pressure release (twisty knob thingy) so you can partially inflate a tyre, but to be honest the amount of control you have is limited (it might as well be an on/off trigger).
One thing to remember with CO2 is that it will leak out of the tyre over a period of 2 or 3 days, although this might not be such an issue with low pressure tyres.