Salt was not the choice of demise but copied this tidbit of web info for you...
HOW TO GET RID OF BERMUDA GRASS TURF
Many people would like to replace some or all of their lawn with more water-efficient landscaping, but don't know how to kill off Bermuda grass or similar turf types. Bermuda grass is very tough, and cannot be killed by simply not irrigating it. You can=t rip it out or dig it up, either, because the roots go deep. Covering it with a tarp or plastic sheets to deny it water and light also is very unlikely to work. In fact, the only practical way to kill these types of grass is by using a herbicide that kills plants on contact.
The most common herbicide for killing grass is glyphosate, sold under various brand names such as Roundup
(Monsanto), Kleenup
(Ortho), or Doomsday (General Control). Glyphosate will kill any plant it touches, so be careful when applying it. The good news is that glyphosate decomposes rapidly, so you can plant water-efficient trees and shrubs where the grass was.
You cannot kill Bermuda grass when it is dormant in the winter. Best times to kill it are Spring and late summer.
Prior to application, irrigate your grass so that it is green and growing, so that the herbicide will move through the entire plant and kill the roots. Apply the herbicide when the temperature is 80 degrees or above, and there is no forecast of rain. Follow the directions that come with the herbicide. Using more than is recommended will not kill your grass any faster. Two days after applying the herbicide, resume irrigating the grass.
Glyphosate will kill your grass in one to two weeks. If it still shows signs of life, a second application of the herbicide may be necessary. Dead turf can be removed by setting your lawn mower very low and "scalping" it, or using a power rake.
Glyphosate will NOT kill grass and weed seeds, so you may want to apply a pre-emergent herbicide after you have removed the grass. Pre-emergents will not harm growing plants or weeds. Do not use if you plan to grow wildflowers from seed, such as California Poppies or African Daisies.
Personally "round-up" is not the best on the market as it needs extreme heat to boost it in the butt. A total vegitation kill will be best, now this is merely for your rock ditch