In the original post, the terrarium that was treated had become infested with centipedes and I mean infested! The post showed pics of the terrarium being filled with the CO2; they had it thick enough so you could not see through the fog.
The "after" picture showed hundreds, if not thousands of centipedes curled up on the surface of the soil; the writer stated that even the eggs were smothered as he did not have to repeat the procedure.
Also, There is a lot of buzz going on around increased CO2 levels and increased chlorophyll / growth. Dry ice is nothing BUT CO2 and if used correctly, should be the answer to increasing the CO2 as desires. Just make sure not to leave the dry ice in the container for too long as it will make the temps plummet. If that happens, I would take the container out and continue to 'pour' the fog into the container until there is no empty space. As the fog is cool, it will almost pour like water.
Again, be careful with the ice as it will get cold enough to cause frostbite on bare skin very quickly.
I really wish the writer of the original post would comment on this - it looked really cool and obviously worked for them.
Well, again Merry Christmas and Happy New Year.
Steve