John, found the Francois quote, from 2011:
It's supposed to be stinky. As long as you use a clean cloth every time, keep the brine covered and in a fridge I don't see the problem. I have no issue keeping solution for 3 months. If it did get really nasty I would just boil it and redose, not make fresh. I do this with brine as well, it gets better with time, even after boiling.
So it should be kept in a fridge , that's good to know , I haven't been using a rag , but a brush instead , I do wash it out well after every use.
And as for the brine , I have been keeping mine out on the porch over the winter , it has been as low as -20 , I have an extra fridge that I will keep it in over the summer months.
I've had the same brine for about 6 months now , and it smells great , I think it really adds an extra dimension of flavor to any cheeses brined in it.
So far it is fine , but I may boil it at some point , if I think it needs it.