We had a batch of clothes we forgot to hang out for a day or so and they got really stinky even after washing a few times, so we got a powder than I normally never buy that was an aromatherapy one and also a fabric softener. I also washed them in warm water and line dried, seems to have worked here although I don't want to use that powder in the long term so not sure if that's going to be a solution for you. I agree that maybe the vinegar and eucaplypus oil might work, or even a dash of lavender oil?