I have used a 1 part salt and 3 parts vinegar, both table grade, with fairly good success. Problem is, it's a pain to disolve the salt in the vinegar and the salt residues clog up the sprayer tips. I only used it on driveways and sidewalk brickwork so microbial activity was not an issue. Round Up is simpler and easier. Don't be fooled into thinking that this is all organic so a pesticide licence is not required. I believe that it is still considered a pesticide as that is what it's usage is.