It's been my experience with liquid carbon dosing, including: Vodka, Vinegar, VSV, VCV, and NOPOX, that they all work. The only issue I had with them was the daily dosing, and constant testing, and adjusing the dosing as necessary. A couple years ago I went to bio-pellets, and haven't gone back. The things I like about it is: I no longer have to do daily dosing, testing is a lot less frequent, it's pretty much on auto pilot(bacteria populations adjust depending on ebb and flow of your load), the bulk of it is contained in a reactor, (as opposed to the whole tank), the effluent can be placed directly at the input of the skimmer.