JRYezierski said:

Ok I have called/emailed lots of places looking for vinegar 10% or
20%acidity and have not been able to locate where to purchase.

Photographic supply places will carry acetic acid at a 28% concentration.
(You can dilute to 20%.)

Otherwise you might have to try a chemical supply company, which might
not sell to the general public and might sell only in huge quantities.

In neither case will these be labeled for use as herbicides, but should be
pure acetic acid and should works.
--
Pat in Plymouth MI ('someplace.net' is comcast)

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)