Vinegar has a plethora of uses, as does any other mild acid. I use it in the kitchen in many culinary ways, it's a cleaner, a disinfectant, and will bring the luster back to stainless steel utensils and frying pans. All of these uses can be readily observed, simple observation and experiment.
However, one should be very, very wary of health claims of vinegar, unless you fully understand the scientific method (how science claims and conclusions are made), biology (how the body works, specifically how it handles both acids and alkalies when ingested) and nutrition (the process by which food material is used by the body).
As far as the internal health benefits of vinegar are concerned, I highly encourage those interested in such things to read the
actual science of it all.
One key aspect: 75-80% of Americans don't truly understand the scientific process and are not scientifically literate, meaning only 20-25% of Americans are “scientifically savvy and alert,” and that most of rest of us “don’t have a clue,” and will
fall hard for junk science.