Bit of both really. The more the salt impregnates into the flesh the longer you can keep it so soaking it in a brine for 24-48 tends to acheive this more than just rubbing it on.Also the longer slower type of smoke will give you longer shelf life as it tends to dry out the flesh a bit more than a quick hot one.. I generally reckon that a 3-4 hour smoke should give you a weeks fridge life but up to 6 weeks if you vacuum pack it and 3-6 months if vacuum packed and frozen.

I had somked blue nose in the frezer for 10 months vac paced done in the good machine Bradley
Was mint az

totally agree fresh water is a no no. after smoking in the fridge up to a week covered with cladwrap. but on average its eaten within a day or so.