I would think that if you follow the directions, it would work just as well, if not better than the power. I've heard that if the power does not dissolve completely, you can end up with spots on your disc. This should not be an issue with the liquid.
"I don't know who started it and I don't give a f***. The one thing I do know is that we did it harder, we did it faster, and we definitely did it with more love, baby. You can't take that away from us." - Stevo, SLC Punk