its simply bs.
the whole flush thing is questioned by some people, i however do flush before harvest.
if the plant has no roots it cannot up take any water, therefor it isn't flushing away the nutrients that are in the plant.
you are supposed to cut the nutrients and just use water, when the plant has used all the nutrients you have fed it, it will begin to eat its self, thats why you end up with yellow leaves etc.
i am not saying that flushing is neccessary, i'm simply saying that this is not a way to flush.
a clone survives because it is a small plant and only perspires a small amount of water from the leaves. a big plant needs more moisture because it loses more, it simply won't pull enough water through the stem to support itself. thats my arguement, the plant will not "flush" properly with this method
So why do we put the stems of clones in water then?for the record though i do agree that this method is silly and as you call it "bs". i just think the cuttings take in from their leaves untill they have roots. i dont think the stem is uptaking the water.
So why do we put the stems of clones in water then?