I have to say....not really! A film also builds up on plastic. The drill is - with whatever bottles cold rinse, warm soapy wash with bottle brush, rinse. If formula feeding you need to sterilise bottle. Breastmilk doesn't easily grow bacteria - it has it's own antibacterial properties. Bacteria grow readily in formula. Many breastfeeding mums never ever use a bottle - they are not a necessary part of life with baby.