Permanently Aching Leg Is There A Natural Weedkiller One Can Put On Gravel And Driveways? Not Proprietary Branded Stuff.?

Is there a natural weedkiller one can put on gravel and driveways? Not proprietary branded stuff.? - permanently aching leg

Whether the land left permanently sterile, but they will not harm animals or children. A large area to cover is so important - although perhaps my back pain is more!