Vinegar with a touch of dish soap works well. Some recipes include Epsom salts, too. Spray enough to coat the leaves, and the plant will start to shrivel and die within a very short time.
If it’s an area where you never was anything growing, AND you don’t mind critters coming up and nibbling at it, you can use water softener salt. But critters will definitely enjoy the taste!
I’m looking at weeding torches right now, and noticed that there’s one available that uses electricity and acts as a heat gun, rather than an actual flame. It needs to plug into an outlet or extension cord, but for stuff near the house it might help. The heat kills leaves within a few seconds. Repeat every time the leaves re-sprout and eventually the root runs out of energy and dies.
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LOL...... sounds SLIGHTLY like the principle that unhappily worked when deer kept eating my hostas each year ...... so many times they eventually were gone. We lost thousands of plants to the deer.