Do I have to use the exact technique that the demo describes? It says small circles with the thumbs at the base of the penis. My intuition says that any technique for stimulation will work as long as it says at the root - lower half or lower third of the penis.
I find light touches on the underside of my penis, still at the root, to be much more tantalizing than the thumbs doing small circles on the top. If I am doing that and I use one hand wrapped around the glands and upper third to expose the underside of my penis, does that undermine the exercise?