First Aeroponic grow.

BAHAHAHAHA When this so-called "technique" was tested, it fell on its face and shit itself badly. Only people susceptible to placebo effect believe in it. All you need right there.

No more than 24-48 hours really. Some people would say not to bother.

Is there a toxicity or a problem? Otherwise don't do it unless just want to be lazy and not deal with fertilizer for 1 or 2 days. The plant's biology depends on a concentration gradient across membranes and cell walls etc. Drastically changing the dynamics of osmotic pressure in the plant is not helpful despite what bruh-science believes. If the plant is healthy, it's fine. "Flushing" in this context will do nothing to impact mineral content of the flower... absolutely nothing and that's a proven fact. Also, common sense because the plant has no biological processes that can do such a thing, lol. It wasn't even a smart hypothesis to start. When this so-called "technique" was tested, it fell on its face and shit itself badly. Only people susceptibly to placebo effect believe in it. it's "faith" and not supported by any evidence.