Actually, their lab tests prove exactly what I've been saying, flushing causes the plant sacrifice itself to FEED the buds. The levels of the most easily transportable nutrients goes UP in the buds. Unless you starve the plant long enough for the buds to die, you accomplish nothing.
And as to their comment about bud tasting like burning hair, well we all know many hydro growers think that when to comes to nutrients, more is better and too much is just enough, THEN they ad 15 other nutes they don't need! It would take weeks of "flushing" to get rid of all the crap they've fed them. Some of the best DWC growers I've seen run LOW nutrients, usually around 600 - 650 ppms. No need to flush buds grown with a little common sense.
Flushing is a total waste of time and and damaging to the plant. Science, plant biology, explains why. And of course a nutrient company will try to convince you otherwise, how else can they sell you "flushing agents" ( now you really are putting Chems in your plants! )........
I've done several grows of organic and nutrient solution side by side and have long offered a bet that no one can tell the difference. Many have tried, no one has ever been able to tell. Flushing is just an old, hippie myth.