I have both flushed with water for 10 days and i have feed CHEMS right up till 3 days before harvest with no flush just drying out the soil.. Both tasted the same, and burned the same. IF you ask me ITs all in the cure. The CHEM stay in the soil ( flushing the salts off the roots anyone) the N is used by the plant and stored in the plant as N.. not as bat poop or GH GROW, but as N. N is N is N.. no matter where it came from once its in the plant. As long as the plant is alive it has NPK and more in it. and you can not tell where that NPK came from, or FLUSH it out of the plant. By flushing you are trying to get the plant to use all the NPK it can , but this will come at the cost (probably a small amout) of reduced growth.