I reuse these bottles all the time, freeze them solid to put in ice chests and as the ice melts, I have drinking water. I clean them thoroughly with soap, hot water and bleach, but I noticed on one of the bottles that it says not to reuse them...what gives? Does anyone know? An internet search revealed nothing. Just curious as to why.

I can understand why you don't want to reuse milk jugs for water consumption, but I can't imagine why you couldn't reuse a container for drinking water...that just had something in it I gave to my child to drink. Especially after cleaning them.