Another baby used bottles - how best to clean? FTM, 38 weeks, baby is almost here!  Today, one of my friends was over and her toddler found my stash of very new bottles.  He managed to uncap one and immediately started sucking on it.  Honestly I'm not mad at all, was sort of cute and he's an angel. Seems like this is an easy thing I should be able to clean but I've literally not cleaned a bottle before, especially one that another baby used.  

What's the best way to go about re-sanitizing this bottle - I don't have a sanitizer?