FG, as a matter of fact, I actually work very hard to keep all magic out of my op. If I can't explain it, I don't do it.
I'm ambivalent about flushing for the most part. I've done it and never found any difference. I even did the closest I could to a double-blind comparison, giving some flushed & non-flushed buds to a half-dozen mates in bags labelled 'a' & 'b'. No one could tell any difference.
Every once in a while, I've got spare tray space which allows me to flower a bit longer than 8 wks. If I were to build flushing into my sked beginning with wk6 as per the usual suggestion, they would start to show some deficiencies after wk 8.
feh... flushing is certainly not a necessity, but I can't really see any general harm in doing it.