Milk + sippy cups can = a terrible odour that is difficult to get rid of with plain soap and water, especially among all the sippy cup “parts.” After a quick search on Pinterest about stinky sippy cups and a few experiments, I discovered something that works well for getting rid of that gross milk-left-too-long in a sippy cup smell.
Put 1/4 cup of peroxide (or rubbing alcohol) with 3/4 cup of water in a mason jar, toss in your parts, give it a good shake, then let it sit until the next time you wash dishes. I guarantee your sippy cup parts will be as fresh as the day you bought them with this technique. Happy cleaning!
Our Life Well Lived - Leanne Hintz 