I get the Feeling that i might bei able to Control the blood flow in my dick with my Mund so that i gain and los an errection whenever i want but i got to Confirm this first
Great to read so many positive comments. But for me, the issue is not being able to get much of an erection in the first place, so this hasn’t been a very useful exercise. But I do appreciate how it can helpful and will try again.
Couldn’t get hard. I know I’m not meant to feel this way, but I couldn’t help feeling disappointed and worried.
Helps boost confidence and feeling more in control with erections.
This was really good for me. It gave me confidence. Excited to try this with my wife!
Felt harder to get it up each time
Good
I couldn’t get hard at all during this exercise
It was really relieving to see how quickly I could recover my erection after it went flaccid and how well fantasy actually worked to stimulate myself.
Wow I could easily regain my erection this time, I hope it works when having sex next time
I loved this exercise. I normally need visual stimulation to get hard but I just relaxed and thought of a couple of past encounters and it worked…so it was nice to know that I can get hard just by fantasising, something I’ve not been able to do for years. I also used lube for the first time and it was amazing. Difficult not to reach the natural conclusion each of the three times, but I didn’t!
I can definitely see how useful this will be to help me overcome ED.
I just wanted to add an update that I haven’t had great success with this on my own. BUT recently with my partner we made a game of this, and it took all the pressure off, turning it in to good fun. (He’s gone away again! Let’s try this… He’s back again.) So I’m a convert to rewiring our brains to the concept of waxing and waning being a natural process. 
Interesting, I had no idea I can get erect on and off like that. I’d advise to also do some breathing techniques as you wait for the erection to go down. Helps simulate what you’d rather focus on in between erect and non erect when having actual sex.
The more relaxed I was, it seemed more effective but have to work in spectatoring
I get hard and let it go.
Focus on the feeling and arousal. When I am rock-hard, I can feel I am at high and can cum if I want. But I just let it wane down.
It somehow tells me, I can in control of erection. Let the arouse flows, instead of focus on erection or not, and the penis will be naturally hard rock as arouse reach to the peak.
Thought provoking.
Great. With one of my partners I’m familiar and comfortable with wax and wane, she has always made it clear that she loves my penis in all its states of hardness and softness. With my other partner though there’s an expectation that sex has to focus on penetration and she is not particularly interested in slower sensuous touch — she’s willing to receive it some but hardly ever gives it to me. So it’s harder to imagine how to dwell with wax and wane with her 
I did not think I was going to be able to be successful at this exercise, but I was pleased with it. I was proud of myself for getting an erection each time after letting my erection go away. I was able to do it three times. I think this is a start to me maintaining and getting my erections when I am with a partner.
I think the exercise will serve its purpose well the more I do it.