I doubt there's anything about sodium nitrite I could tell you that you don't already know. Can it work? Obviously. Will it be horrible or painful? I honestly don't know. You've spent a lot of time researching this method, and if the reports indicate that a larger dose is more tolerable than a smaller dose, then I guess that's the way to go.
Since nitrite is used to create nitric oxide, which widens the blood vessels and lowers blood pressure, a large enough dose could make you pass out before experiencing any distressing side effects.