That the third technique is the most ridiculous. While you are right to ask whether it should even qualify as a technique, sitting down and breathing, the others are more absurd.
The first has damaged people's eyes. At least the way I was taught it. The newer version, without the pressure, produced no light.
The second was just adding the muscle vibration of your fingers and arms to the background tinnitus. At least the way I was taught it. Take away the beragon or knees to rest your elbows on, as in the revised version, and it becomes a painful game of how long can I hold my arms in this ridiculous position whilst ignoring the discomfort.
The fourth, bending your tongue back. What can I say. Nuing. Nuing a or. So stupid.
So the third, not even a technique, is the best technique.
It used to be described as turning your senses within. But I have at least five senses. Only four techniques.
Was I missing something? I think I was.