I have the Ameda Dual HygieniKit Milk Collection System and Dr. Brown's glass bottles. In the cleaning instructions for both, it says to sterilize before first use and clean with soap and water after every use. Yesterday I was talking with some moms and one said that you only need to sterilize once a day, not after every feeding/pumping session. Should I be sterilizing even though the instructions say just to wash with soap and water? Do certain pumping systems and bottles not need to be sterilized after each use? FWIW, I wash the pump parts right after I use them, and the glass bottles either right away or within a few hours, but at least rinsed first.