Yep.
But is finishing on lower nutes - technically - a flush?
Sounds more like a diet to me.
Calorie counting in contradistinction to a colonic irrigation.
And the whole point of a flush isn't to lower the nutes - its to CLEANSE the plant.
An end-of-life detox.
To rid the plant of excess salts and synthetic nute buildup, to improve the quality and taste of the end product.
Those that grow 100% organically tend not to need to flush.
So yeah - some say to flush with pH water, some say to flush with plain ol' tap water, some say to reduce nutes, some say don't flush at all prior to harvest.
The only thing that matters is what YOU say.