Canna flush and general flushing?

I just wondered if any of you have had experience using canna flush? in my past grows i've flushed with just water for the last 2 weeks and the results were very good..
With canna flush they recommend just 1 week? surely it's just more chemicals so your going to taste it in the smoke, but it's tempting so i get a extra week growing.
Just wanted your opinions becasue it would be a shame to ruin my grow it's looking rather tasty.
this is it 2 weeks into flowering :)

From my understanding flushing agents use enzymes to break down all the chems and help pull them from the plant. Leaving a better tasting and smoking product.