Quote Originally Posted by tulip View Post
I don't see how those can be cleaned thoroughly, even with special tools.
Have you seen the brushes? They're made for the purpose. You can clean the inside of the drink tube as thoroughly as you clean anything with a brush. Your teeth... your chainrings...



And like I said before, HEED is notorious for leaving traces of flavor. I'm surprised you haven't noticed it in your water bottles. I sure do in mine. But I like the flavor, so I don't mind the traces (and anyway, it's usually more HEED that's going in there, anyway).