Doing this will help spread the CO2, but my point was that little CO2 will dissolve into the water column in the first place.
Excel is going to be much better in this case.
Manufacturers say/claim many things. If you want, you can try to use this product; I am just advising that you save your money.
I get what your saying, the co2 tablet is not a permenant solution but more of a trail run to see how good it works. Test the water by taking 2ml of water and add 2 drops of a drop checker reagent (Dupla permanent CO2 Test) before adding a tablet see if its blue, green or yellow. Add a tablet wait a few hours and test the water again if green, hooray, if not add excel. I know it not accurate, but that the only test reagent I got.