I'm not going to get into this debate, My idea's and thoughts are just that, But I used to flush (leech) my plants out before harvest, I saw a grow-room where the guy didnt , I asked how long he flushed for and he laughed, We smoked some weed and it was great, his buds were bigger and healthier with the same basic setup. After the first run I realized it was some stoner myth and a way for nutrient companies to sell you even more shit you dont need.
Same strain same everything, but I didnt flush the plants the last two weeks , I ended up with almost 2 more ounces. It was dried and lightly cured and it tasted better then it ever had. It was perplexing at first until I realized that starving your plant of nutrients that dont readily get removed with water anyways in the last two (most important weeks) is almost an act of lunacy . I've not flushed anything since then and had better tasting and more robust yields.
Now I believe that a proper slow dry and cure contributes to the taste far more then anything else you can do to the plant. But starving it the last weeks of it's life is only killing the potential of better yield.
IMO , Flushing is for toilets .
BB