I'm a bit wary of commenting outside my remit here; it makes me weary

The trouble is in part, it seems, that I'm commenting from the other side of the Atlantic. E.g., this is the first time I've even heard of "canning salt". Thus, it would be difficult for me to comment on your local brands of vinegar. What I've done is read the label and avoid ones that mention sodium bisulphite (bisulfite your side of the pond). (EDIT: sometimes there will be an E-number - in this case, E223 - instead, but that's a European thing.)

[Please note that sulfate/sulphate and sulfite/sulphite are two different things and difference of even one letter in chemistry can make a huge, even fatal difference. Fortunately not fatally so in this specific case, though.]

Where I am the strongest vinegar is generally the stuff from Poland, so learning enough Polish to read labels comes in handy. Sometimes there's Czech or Slovak stuff as well but you kinda get used to Eastern European languages.

Fortunately I'm able to be food grade citric acid monohydrate in huge bags from my local Asian grocers, and, e.g., department stores also carry anhydrous citric acid for descaling which - I trust at least - is almost certainly food grade.

Basically I'm always on the lookout for OTC items which may be re-purposed for the laboratory so I don't end up running around with my extraction tek shopping list like some headless chicken. And tbh several decades of chemistry experience helps rather a lot as well.

Sorry I don't think I can be of any more help than that!