If an image of a woman pops up inside my mind and I focus on it, the normal course of action is to have an orgasm, because that’s my conditioning.
So I made an experiment. The minute a fantasy popped up, I rapidly substituted the mental image with a neutral movie: myself configuring a computer modem. I concentrated as much as possible, actually imagining the single actions, and feeling my arms touching the cables, typing into the keyboard, and so on.
It worked. Within 10 seconds I lost the erection, and the image was gone. In short, I was able to influence my body by diverting my thoughts in a controlled way towards a neutral image. There was no “willpower” involved, just the initial intention. I worked with the natural processes of my brain, not against them.
I did it almost 10 times today, and it always worked. I may as well be onto something here, because the 3-4 hours after an orgasm have always been terrible (cravings) otherwise. I also kept myself occupied with writing and planning some projects. But the technique was useful whenever my mind drifted.