here is what i found....
# Bleach - Not only is bleach a spot remover, it is a weed remover as well. Place some bleach in a spray bottle and spray on the weed you wish to remove. The bleach chemicals will evaporate or dissipate in about two days (or less but better safe than sorry), making the area safe for planting. Again, bleach will kill anything but if you do get some on a plant you want to keep, just wash the plant off.
# Vinegar - Vinegar is a great organic homemade weed killer. Either white or cider vinegar will work. The acetic acid in the vinegar works to kill the leaves on the plant but not the root. Vinegar will kill back (kill the leaves but not the root) any plant but works best on young plants because they do not have enough energy stored in the roots to regrow their leaves. If vinegar is applied to more established weeds enough times, the plant will eventually deplete its stored energy reserves and die.
# Salt - It was once a known war tactic to salt the fields of enemies. Salting the earth was also used as punishment for severe crimes in several countries throughout history. The reason is because salt will kill plants and will make the ground unsuitable for future plant growth. On a small scale, you can drop a small pinch of table salt at the base of the undesirable plants. It will kill the plant but will dilute down to harmless in the next few rainfalls. On a larger scale, you can cover your gravel driveway or your ex's yard with a good amount of salt and nothing will grow there for months. (FYI, it is illegal to salt another person's property. It's called vandalism.)
and here is a ampther recipe using all 3 ingredients......
Mix 1 gallon white vinegar, 1 cup table salt, and 1 tablespoon dishwashing liquid together and spray on weeds. To do so, remove approximately 2 cups of vinegar from the jug, pour in the salt and dishwashing liquid, then return the 2 cups of vinegar to the jug. Close the lid and shake to mix.
Transfer to a spray bottle (after shaking to mix the ingredients) as needed. It works as well, if not better, than Chemicals, but is much cheaper. Be careful, it will kill whatever you spray it on!
If you go purchase vinegar, 10% acidity, 20% acid would be better, and spray it on the weeds in the heat of the full sun, you will have an effective weed killer.