I read that a solution of 20% acetic acid vinegar makes a good weed killer. But after an hour of on-line searching, I cannot find where to buy it! I worry about buying the full strength; it's pretty hazardous.

Any suggestions? The advice about "farm supply stores" was not very helpful.

Now, for a really dumb question: what would happen if I used muriatic acid? That I can easily find at Home Depot. But I fear that this would be worse than using herbicides.

I'm not too concerned about "good" plants being killed as the bulk of the weeds infest my gravel in the front yard (trying to cut down on watering!).