In most of my travels where water is an issue or drought is ruling or where reclaimed is the coming possibility, we have to deal with management of salts. So that can be the #1 driving force in deciding to flush to rid us of conductivity.
The second thing is that a majority of the modern courses built in the last many years have a form or another of a perched water table-oriented sand-based system. And that is its own animal, requiring some technique in water application to infuse air into the rootzone.
Lastly, with topdressing seen as a best practice over (again) the last many years, we see greens that have their own layered version of a drainage free water table perch. And that requires some thinking as well.
Since Ive been (mostly) a Western US Turfhead, we have tended to talk about this a lot. As a young super in Denver, having just put in one of the first Maxi systems and starting to water with ET, I didnt know that my deep wells were of pretty poor quality. But I did know that light frequent apps of water oriented toward ET werent giving me the playing conditions I wanted. It was right about then that I heard that Ed Miller, who once was in CO and was then in AZ had written an article for the Green Section Record. Here it is: Ed Miller Article. I hope you read it and read it again.
Reading this and adopting this method on my push up Poa greens and even on the rest of my golf course as we began a much more aggressive aerification method turned a lot of things around for me. So Ive stuck with that, both as a Super at two other positions and over a bunch of years of consulting. Its not a new thing. Its not rocket science. It does fly in the face of how some of the modern software works, but we get around that.
The flush is still important and I think over the last 5-7 years, water quality hasnt gotten better and air always needs to be exchanged in the rootzone. So a real honest to goodness Irrigation Sneeze is really important. When that is coupled with some common sense about how Evaporative Cooling really works and how water moves and how salts accumulate, you have to think that perhaps a change is needed when the usual method isnt working.
After all, the true definition of agronomic insanity is when you keep doing the same thing and the same bad stuff keeps happening. As turfheads, we tend to want to change a lot of things, but foundational comforts like watering tend to be more more holy and less prone to some critical examination.
Over the years, I've helped a lot of people out with this technique and have come to believe it has a reasonable place in a majority of situations. Ive seen it give us some problems when irrigation systems have poor DU, poor control and when weather demands some respect for already humid conditions. We have control over a couple of those areas and the other one is cyclic. Popping off a big cycle in 90/90 weather is the kind of thing we dont really want to be doing. But for the life of me, I cant understand why the water goes on every night in 70/30 weather. Cant.