Flushing is an interesting one.
Every once in awhile my plants will look like shit. Simultaneously showing nutrient burns and nutrient diffincies and looking over watered. If I water until run-off, the run-off comes out a gross piss yellow. As if there was gross poison in my pots and flushing cleared it out. Then my plants perk up and look good again.
Hydro guys often feed/ water, feed/water... In effect "flushing" out the old nutrients with plain water, then starting over with fresh nutrients. Who know what kind of ph or lockout issues you can develop dumping those weird ionic compounds or "nutrients" (bro science alert!) on top of eachother for weeks.
I don't know about 2 week flushing protocols to increase dankness, or special flushing chemicals. But you can Certainly flush to eliminate undesireable buidup and Stop fucking your plant up.