Shadow, your profile shows you are a pilot but with imagination like yours, I feel you are wasting your talents.
The easiest way to do that explosively would be to surreptitiously take out a window (or two) with a pen-gun (pistol barrel disguised as a plastic biro or fountain pen and utilizing a spring-loaded firing-pin onto a lead-pellet charge). It would just sound and appear to be a window blowing out.
Next time you see an engineer, ask him to explain the cabin window construction to you. What does a window blowing out sound like?