>Highly testosteronous men like me can't make it past a week.
You are just addicted. To break the addiction, you must learn to resist the urge through logic, reasoning and dispassion. Meditation helps. Remembering why you turned to nofap helps. Cold showers help. Eating less helps. On top of that, finding productive things to do and dedicating yourself to them is the key. Work, study, gym, etc.
Newton gave a great tip on how to deal with nofap: “The way to chastity is not to struggle directly with incontinent thoughts, but to avert your thoughts with some other employment, by reading or meditating on other things, or by converse, for he who is always thinking of chastity will always be thinking of women.”
>My question is: Has nofap hardmode worked for anybody at all?
I was a chronic fapper for two decades and made it to 30+ days no PMO multiple times since I turned to chastity. So I know for fact its possible. The tough part is making lifestyle changes so you're not repeating the same motions that usually lead to relapse. You will know what they are, whether is binging on spicy food the night before or wasting all day lurking on the net.
Nofap in essence fills your body with energy. Its very potent energy that wants a purpose and work. Newton, for example, worked 18 hours a day, 7 days a week. You need to find something similar, a purpose to your life to dedicate yourself to and then transmute the energy to achieve your goals. If it won't find a productive outlet, or a spiritual outlet via meditations, it will seek its release via the usual sexual ways, and that is a waste. The struggle for former sex/fap addicts is to avoid that and find things to do so you don't even get the time to relapse.