Step 1: Supplyes
Vinegar - any kind will do
Bicarbonate of soda - baking soda
Airsoft bbs - optional - the boom scares them enough, the bbs are just for bragging rights
A small airtight container with a strong held tight fitting lid - NOT like a film canister!
A ziplock bag - you just need the corner
And lastly, two hands (have someone help if you only have one :)
Step 2: Assembly
Now take one corner of the bag and put roughly half a spoonfull of baking soda into it. Take the bag and slowly push/twist it into the container, the baking soda may rise a little but you should have plenty of bag left. Once in, leave enough bag to be held down by the cap on all sides after cutting. Lastly, fold out the bag and screw on the cap. This is so it doesn't explode in your pocket while your running.