I use Oxiclean too but I don't let them sit too long. once I left them in there for a day or so & got a film on my bottles, I think from the labels/glue & that was a pain to get out. I also try to fill my cooler up to the neck of the bottle but not over the top to keep the dirty label water out of the insides of my bottles. after that I run mine thru the dishwasher without soap on the hottest cycle.