In a nutshell, no. It's not a cleaner. Oxi, PBW, BLC, etc. are cleaners. BLC is actually called Beer Line Cleaner.
Star San is not effective unless it can penetrate the gunk. Cleaning is necessary to remove gunk to make sure it's contacting all bad cells and destroying them. You might run star san through a hose with a bit of mold in it, and then find out later that the mold loosens up and allows the bacteria to grow. (Although to be honest, it's a small chance after the beer has been fermented and kept cold in a fridge...)