..............My idea was to drop dry retardant such as jello mix just for affect.............
========I have experimented with carpenters chalk that you use in chalk lines. they make it in red. I wrapped it in plastic wrap and put it in the bomb bay to keep from making a mess. It looks good when the bag opens. Dropped some that the plastic didn't open and the package dropped right to the ground. I think the mechanics of it could be worked out for a good effect. Probably cheaper than Jello also, but the chalk dust is heavy.
Randy