I agree with HighAltitudeOrganics, they are probably drowned.
Not sure why you thought they needed flushing though.
Also, remember this; each healthy green leaf you remove will reduce your plants capacity to produce energy. Energy that is needed to grow bigger and better flowers. Try removing only the yellow leaves, for once they are yellow, they have served their purpose. Plants can not "channel" energy. They do not have a brain.
Defoliation is an absurd idea and the most commonly mis-understood issue when it comes to cannabis cultivation.
Fewer healthy green leaves = less energy produced = less growth. It is that simple. Those leaves you think are shading "bud sites" are actually the power station making the energy for buds to grow! Remove the healthy green leaf means that "bud site" must now get its energy from somewhere else, resulting in slower and smaller growth. Your plants first "instinct" is to grow new leaves to replace the ones she has lost. This takes energy. Energy that could go into flower growth had that healthy green leaf not been removed for no reason. Cannabis did not evolve over 1000s of years to shed healthy green leaves during any stage of its life. Only old yellow leaves fall off. The plant knows what it is doing. Please leave the healthy green leaves to produce the energy for your plant to grow her biggest and best flowers. You might be surprised by the extra size and quality of her flowers if you do leave the leaves. Hope this helps.... Organoman.