A nail will rust faster in water but in salt water you need to watch the rate of mitosis in weather the salt will stay in the water vinegar will have a opposite result but still a reaction will occur in the nail will go black.
Regular water
Willa nail rust in vinegar ,salt water or both
Vinegar Water
How much vinegar is in the vinegar water??? And how much salt in the salt water??? It depends on how diluted the solutions are.
The vinegar will explode if a nale is put into it so I suggest not trying to find out