So, suppose that before putting the cap back on a 2 liter soda bottle that I have just used to dispense soda, I were put my lips around the spout, suck in, hold that position for as long as I can, and then blow out, and then put the cap back on. The idea is to try to fill that gap in the bottle with 5% exhaled CO2 instead of 0.04% atmospheric CO2.

Would this significantly delay the flattening of my soda?