Chlorine bleach and ammonia are far more toxic in the garden than a broadleaf herbicide with Trimec. All of the remedies you mention--bleach, ammonia, salt, and vinegar--remain in the soil and can damage not only the weeds you're targeting, but all other plants that you'll ever try to grow on the site. On the other hand, products like Roundup are designed to become inert when they contact soil. That means they only harm the plants they touch. I know you'd like to stay away from a chemical herbicide, but you'll be much better off with a broadleaf weed killer (look for one with Trimec) than any of the alarming remedies you mentioned. Unlike Roundup, broadleaf weed killers target only broadleaf weeds and won't harm your turf grass.