Ok, so a few months ago, I started doing this, more out of how good it felt, but noticed it made my erections harder and penis seem thicker. So I stopped for a few months, then started doing it again recently, and it seems to have the same effect again. I'm not sure if this is a fluke, so I wanna see if other guys do it, and get similar results. What I would do is take a shower with hot water, as hot as possible to shower with. after I'm clean, I'll get hard and stroke. Then, ever minute or so, I'll make the water slightly colder. enough that it's a noticeable difference. while doing this, my penis never looked or felt bigger, by the time the water is cool. Doesn't require much other than a working shower, and I'm curious about other people's experience doing the same thing.