Note that this product is both a cleaner and sterilizer. The contact times on the label seem to be more directed at cleaning so it's difficult to figure how much time is required for sterilization of a surface that is already clean. Lacking any better information, you must trust the manufacturer's instructions.
The sanitizer that you see people swishing about is indeed Star San. It contains a surfactant so it coats the surface, which allows for proper contact time without total immersion. The official recommended contact time for Star San is two minutes, but Jon Herskovits of Five Star Chemicals has said on the Brew Strong podcast that 30 seconds is sufficient.