So I did a stupid thing: I let the bottle I use for powerade mix sit after a ride with the lid open. It grew some mold real quick like. Ok, well I did let it sit for a few days.

Anyhow, the lid and the bottle have several spots of mold and so far I've tried boiling water with baking soda and that didn't seem to make a dent. Tried running it through the dishwasher on the heavy wash setting. It made a small dent, but not much. Maybe a toothbrush for those tight spots?