Originally Posted by
Riveting
I challenge anyone to take a Q-Tip to the crevices of the spout's underside on their bidon (and/or their travel coffee mug mechanics) and come out clean. We're all drinking the black stuff, just some more than others. And FWIW I no longer buy travel coffee mugs that have large hidden crevices that are impossible to get a scrubber on, ever since a 1"x.5"x2mm piece of coagulated slime/black-stuff came out through the mouthpiece, and had probably been collecting there for dozens of morning coffees. I don't mind seeing a little black-stuff, but I definitely don't want to feel it writhing around in my mouth. Sorry for any dry heaves that may have caused.
I only put water in mine. I will occasionally notice a little slimy feel if I haven't cleaned it recently, but no, there's no black stuff. Dirt get on the outside of my bottle, and that is often dark, but it's not slime.
I'm not claiming my bottles are sterile, but no, they're not dirty inside like that.