Coke is very acidic so would dissolve rocks and mineral deposits. It is a good oven or toilet cleaner for that reason. Not sure it dissolves matted plant material but it might.No, it is not just the bubbles, because gingerale or sprite, etc, doesn't work. Something in COKE (pepsi works a bit, but Coke was the 'winner' in clearing feeding tubes by far.) There is something in it that helps eat away at the blockage. [note: warning for those of you who drink a lot of coke...it can/does eat away at stomach lining if too much/too if too often consumed!] Coke is definitely acidic.
Edit: They also mentioned 'cellulose' helps, too, in one of the articles. That didn't make sense to me as I thought cellulose was fiberous? And it wasn't clear if it needed to be prescribed or if it was something readily available.