I wouldn't believe stuff from the internet without a reliable source.
https://en.m.wikipedia.org/wiki/Carbonic_acid
Wiki confirms what he says partially, though I'm not sure how you can apply this.
From what I understand you need precise measurements, because if there's any water left the carbonic acid will revert to it's previous state.
I see he refers to a biological reaction
But as you can see, by adding carbon dioxide to water, you don't get carbon dioxide plus water plus carbonic acid. What you get is carbonic acid and hydrogen.
I don't see anything about it being dangerous either. I'd look for something else if I were you.