No, the bacteria doesn't really live in the water, it lives on surfaces. That's why it takes so long to build up in a new aquarium, because its not there in any significant concentration.
So, the directions say that it needs to be CONTINUALLY added means that its not actually cycling the tank, but dealing with the ammonia another way. If you are willing to use that constantly, then it should work, but I don't think that's an effective way to cycle a tank. Eventually it will cycle on its own, but not in the time frame that they state.
It does work well for a mini-cycle though - for an established aquarium where an ammonia spike comes unexpectedly. It can deal with the ammonia while the bacteria build up their population again.