idea found here
EDIT: The link above is dead. Sorry.
And wow, Its been awhile since I posted this. Since then I've found that, even with corn instead of BBs, this doesn't work except in scenarios where the triggering of the device itself is considered a kill, at which point you might as well leave in the confetti.
Step 1: Supplies
4.long thin object(like a knife or pencil)
Step 2: Make
You will need that later.
Fill with BBs.
Replace paper circle.
Step 3: Setup
tie fishing line to the end of the popper string.
run line accros chosen space.
Expeirement to best suit you needs.