I’ve got three of them all of them are used; so I want to sanitize them well because who knows what kind of diseased backwasher used them last. I read about putting soap in them and shaking them, and bleach and shaking them, and boiling them. I’m kind of worried about bleach leaving a bad flavor and boiling could melt them. What would you guys recommend? Another thing how can I tell if they’re USGI they all look the same but are made by different manufactures?