I thought I would contribute a thought or two to this topic - but they are only notes from someone who knows little.
Until a very few years ago I had only known a few people who complained about reflux - just slight acquaintances. Then my partner, who had never previously had it, suddenly started to suffer quite a lot.
Her doctor prescribed Ranitidine but something made us question that (and she never took any of them). She saw a gastroenterologist (for that and many other gut problems) but he didn't say or offer anything useful.
The context for her reflux (and other problems) was hypothyroidism. This had recently been diagnosed and she was being treated with levothyroxine.
Knowing next to nothing about that, I did a lot of research. One of the oddities that I kept on seeing was the use of vinegar for reflux. This sounded silly and for ages I just ignored it. But we did eventually discuss it and she decided to try. One teaspoonful of organic cider vinegar in a very small glass of water. Shoosh it round her mouth and swallow.
From that day onwards, she took it very regularly - sometimes a few times in a day. It helped enormously. For some months she would get up most nights and take some. Gradually, probably as her hypothyroidism treatment built up, she needed it less and less often and her reflux resolved.
One very interesting thing I came across was a cryptic Russian research paper suggesting that hiatus hernia is a good predictor of thyroid disease.
We also question whether her problem was really more to do with having low stomach acid (common in hypothyroidism) rather than too much. Seems that is associated with the muscles preventing reflux not working properly. (Actually seems that all the PPI, anti-acid and other medicines may be just what a hypothyroid person should be kept way from!) But there again, hypothyroidism causes weak muscles itself.
Anyway, the very last thing I would wish is for anyone suffering from the 'other' forms of reflux to take vinegar and suffer. (One place I mentioned this before, such a person said that they had already tried it and been in considerable discomfort for the rest of the day).
Another person in that same place tried it and it appears to have resolved the reflux issues he had been having for years - that his doctor and specialist had failed to make manageable. He actually tried other vinegars and found they worked - maybe not quite as well or not as pleasant to drink.
So if anyone I knew had hiatus hernia or reflux, I would first encourage them to ask their doctor for a thyroid test. Then, maybe, depending on the test, them and their circumstances, I just might suggest trying a drop of vinegar.
Hope someone gets something useful from this.
Rod