I tried the apple cider vinegar when I had a migraine that would not go away. I took a teaspoon in a glass of water and it didn't seem to help. A few hours later, I tried again with a bit more - about a tablespoon this time.
I also decided at that point that I had a craving for chocolate, so I had two squares of dark chocolate. The migraine was almost totally gone within a half hour. I searched online and found out that chocolate contains magnesium, which is good for migraines, plus it elevates serotonin; low serotonin is thought to cause some migraines.
I'm not sure which helped more, or maybe it was the combination, but after 24 hours, I can finally function again!