If this stuff does work, you will need to maintain the tank with an ammonia source. This can be fish or shrimp (probably not the best choice since they have a very small bioload) or snails.
A good way to test if it is actually working, find pure ammonia, and add it to the tank. If your water tests clean for ammonia the next day, then this product is actually working. Technology has come a long way and some products can help speed up a cycle, but the only ones I've heard positive reviews about are Seachem Stability and Dr Tim's One and Only. Even if someone claims to be a great aquarist, I always double check the advice of people trying to sell me something.