I just did my final flush last night. IMO it helps speed up the process of getting the buds "ripe" It washes aout any excess nutes/salts build-up in the soil. It also forces the plant to use up whatever nutrient reserves it has stored within it's self. I run a gallon of water through, and let it soak for a good 15 min. This lets those salts/nutes dissolve and be able to be flushed. I then run copius amounts of water through it (I use my bathtub water) I flush the pots out a good 3 or 4 times, and then I took a gallon of pH adjusted water with a tbl spoon of black strap molasses in each gl. This was the final rinse. The plants should be finished in 7-10 days. There are many people here that don't think a flush is neccessary, but I'm one of the ones that do. The one time that I got my dates messed up and didn't get a flush in my friends did not even believe that it was the same weed as before...so it must do something to the taste. I also feel that if you are feeding chemical ferts, that it is a good idea to wash all that crap out to. To each their own!