I haven't believed in cannabis specific anything for quite awhile now, its all BS. If you want to read more , search for agricultural leaching studies, it's almost never referred to as "flushing" by actual horticulturists. Cannabis an annual, herbaceous, plant, not some magical alien species, and should be treated as such.
Science has indeed gone a little sideways on us.
My problem, really, is this--
The only other plant regularly grown to be smoked is tobacco, but of course it's value is in it's leaf, not it's flower. And then it has a highly variable curing technique.
The flowers we do grow are not typically smoked.
Hops is grown for it's flower resin, but between tobacco and hops, neither matches cannabis.
So far, I see a lot of studies regarding leaching salts to reclaim fields, that leaching removes npk from the soil frim excessive water...
Largely, I'm having trouble finding anything whose conditions are at all comparable.