Ultimate CO2 Machine
The system I'm about to describe could be changed to suit your environment, needs, and taste. It's whatever your imagination will conjure up. As long as you stick to a few simple rules. My system slowly disperses CO2 out for a day or days.
This is my system. You can make it smaller or bigger. I have a 32oz cup which I fill it with a cup of baking soda. I get 12oz cup and fill with white vinegar. Place the 12oz cup of white vinegar and place it sitting above the 32oz cup of baking soda. Take about 10 inches of tissue or toilet paper, dip it into the vinegar, and place over the side, so the tip of the paper is just below the bottom of the 12oz cup. The paper will absorb the vinegar and begin to drip. Every time a drop of vinegar hits the baking soda, the reaction begins and CO2 is made.