Ill use my glass bottles at home & plastic for out & aboutI only reuse glass bottles and a quick wash is fine just make sure after washing they get a good rinse
Why couldnt u use them forever?I use glass at home to store in bulk but reuse plastic ones for out and about. I just wash them well and rinse thoroughly and air dry but only 3 or 4 times then I bin them and use new ones. You can sterilise them if you are picky but I don't think its really necessary as they aren't a long term bottle.
Apparently the plastic degrades over time and can leech into the liquid. Or so I've read !Why couldnt u use them forever?