You meant PBW, right? Powdered Brewery Wash is a cleanser. A cleanser is for getting all the physical "gunk" off of the bottles. No matter how clean you get the bottles, though, you still need to sanitize (not sterilize) them. That's where you could use something like Starsan. In fact, if you're meticulous about rinsing out your bottles immediately after use, you may not need to clean them any more than that. You'll still want to sanitize them, though.