Ain't nothing as eco-friendly as hours on our knees with a screwdriver.
Well, unless it's 2 inches of coarse mulch.
I suspect that vinegar is not very selective and would kill flowers and crops as easily as weeds.
If you use vinegar often, you would probably acidify your soil. Maybe counter that by using ammonia sparingly, occasionally, as a spot treatment for weeds in the area that was acidified by vinegar.
