In reply to jonoh:
I had one that was a bit stinky that I machine washed with techwash a couple of times: came out OK, but if wet and warm (ie most of the time when walking) the straps would still honk pretty badly.
In a "do or die" attempt to fix it I soaked it in a bucket of dettol for a few hours before washing it again. That did the trick!
It's not waterproof (but I use a liner/drybag inside anyway), but it still manages to carry a full load.