I get a four pound box of table salt at Sam's and try to get it on the leaves and blades of grass. This is obviously in an area where growth of any kind is undesirable, ever. You would be just amazed at how much salt can be tolerated by elm suckers after a tree has been removed.
First, re the vinegar.
Edgar, a few years ago I had to get rid of morning glories. The suggestion dys made was a flame thrower, and he wasn't far off.
I did make a solution (found on the interweb) of water, dishsoap and vinegar....actually I think there was salt in it too.
It killed enough of the plants that I could much more easily pull the roots up.
I thought the smell of the combination of the dish soap and vinegar was nauseating. If I thought the full strength vinegar alone would work, I'd go with that. Even if you don't like the smell, it fades quickly.
roger, another use for salt that seems to be working....flea control
I scattered fine salt (sea salt that wally didn't like), about a pound, all through the carpets, and left it there a couple 3 days before vacuuming it back up.