Salt does kill and prevent microorganisms from growing by drawing water and other moisture out of the food, however you need a lot salt for this.

Back when salting meat was a common practice, meat was salted in tens of lbs of salt all packed into barrels or boxes. When it came time to use the meat, it was rinsed many times to remove the very salty taste. Still a slice or two of salted meat had about 4x times the recommended daily sodium content....which has it's own health risks. Even though in theory, the salt preserved the meat, many people died of food poisoning.

To answer your question about salt used in canning (by any method), the amount of salt required and the fact that canning enhances the salt flavor, you could not use enough salt to help anyway to kill any bacteria due to the chemical reaction with water and also due to the simple fact, the food would be so inedible due to the extremely high salty taste that would make you physically sick.