Can I reuse those plastic water bottles?

Sorry about this one but not really.  Experts say that it’s too hard to get the inside clean.  So I guess if you are pouring the water out of the bottle into something else then you can refill it and reuse it.  If you put your mouth on it you can’t reuse it.

Here’s my issue though, I can’t find any bottles to send water in for my 6 and 4 years old.  They can’t handle a thermos yet but they take water in their school lunches everyday.  I have tried the metal water bottles but they make the water taste funny and I can’t really get those tiny straws clean!  They boys don’t always get those kid sized water bottles closed all of the way and they leak out into their lunch bags and backpacks.  I refuse to send juice boxes and Capria Sun drink bags in their lunches everyday.  If you have any suggestions please leave them in the comments.