Open the lid that is on the jar and put the aside for the time being. Next, fill the the jar about one-third of the way up with vinegar.
Poke a hole in the lid of the jar. The hole does not have to be any bigger than a tip of a pen, Next, tightly secure the lid back on the jar.
With the paper towel, create a pouch. You can create the pouch by folding the corners inward. Once the pouch is created, you will need to fill the pouch with the baking soda.
Next, tape the paper towel filled with baking soda to the lid. If you want to see it work, shake up the jar and point the jar at the fire you want to put out.