This sucks. I have powder in the cup. I add water. That whey is in there for less than 3 minutes before I already drank it all and washed the thing out WITH SOAP. Then it sits in the fridge for a few hours, until I leave work and go home. The next day, it smells rank. Like I left the whey mixture in there overnight or something. But not every shaker cup. It's hit and miss. And some of the misses aren't even fixed with the dishwasher. Do I need to take further precautions than scrubbing the thing immediately afterward with soap and water?