I am a big fan of Hammer Nutrition stuff. SO is sponsored by them,so I use it too. I love Heed. It got hot here, so I mixed powdered Heed and ice water in my camelbak for my mountain bike ride last week. When I got home, I poured out the dregs, rinsed it well, and hung it up as I always do in the garage. I have been on the roadbike for the last week so haven't used it. So I went to refill it today and when I opened it some green nasty miasma of a smell wafted up. GROSS. I guess I had a bit left in there which cooked for a week. I washed everything well with the camelbak cleaning stuff but I think it is a goner unless anyone has any wonderful ideas. I have found that if I don't wash (like in the machine) my bottles directly after use the Heed smell really sticks with it, even after washing.
I did try vinegar too, but this just make things that much worse.