Trust me, I barely noticed the pain in my throat, it was nothing compared to the nausea and the vomiting. It was a minor symptom, and was more of an irritation. The reason my throat hurt was because I swallowed the sodium nitrite soup. But in all honesty I don't remember it very well, because it didn't take long until I puked it all out. The puking could have also caused it, or made it worse. My advice is to take the sodium nitrite with gel capsules.
I am positive that it was my esophagus, because I had no hard time breathing, or at least I think it was a minor symptom. But in all honesty, I don't remember having any problems with breathing. Swallowing was mildly painful, another reason to assume it was my esophagus.
Also, I advise you to get something against the nausea, maybe some medicine. And never do it at a place where you can get discovered. But as bad as this method may look, it was actually a very quick method, and according to the nurses a very reliable one too, if you don't get discovered that is.