I’ve never seen anything significant to back the efficacy of ACV. If a substance found in ACV was useful, we’d have isolated it.
Baking soda WITH ACV is just mixing acids and bases. If you have reflux, sodium bicarbonate tabs are awesome because you’re shifting the acidic environment in your digestive system to be immediately more basic.
ACV relies on the alkaline tide response, which doesn’t seem like it works well.
Most people are sold on the idea of ACV before ever trying it. By the time it’s used, there’s an extreme confirmation bias.
There are a few “studies” but most of them have flawed variables.