ROFLMAO - oh...........are we supposed to wash them?? The only time mine get washed are when I use any type of sport-drink. I don't use any sweetened drinks but any water I put in the bottle after I use the mixes has the flavour of the mix. I'm looking at my winter commute bike right now and it still has water in the water bottle from the last time I rode it.......in March I think?? Guess there are advantages to living in the dry southwest! lol