Don't flush. Flushing is ancient wisdom with no real basis in reality. The salts that are a part of the plant are there for its life. It can't evaporate, the plant doesnt break it down, and it's not like the plant will leech them back into the soil. Flushing just robs her of the nutes she needs at the end of her life which can lower your yield and potency. There have been studies done on it. Smokers actually prefer the taste of unflushed bud and there is no difference in harshness or makeup of the ash.