ok if i understand your question here is my answer:
You need to flush to wash out all the impurities in the soil as well as in the plant itself. This will make the weed taste better. I have even read about giving it a taste if for the last 2 waterings you give it some watered down juice.

Gornik: sugar water or molassis water will only sweeten the bud. Its mostly needed during VEG because its a secondary sourse of sucrose sugar which she needs and makes during photosynthisis so your actually helping here out at the same time and it will increase yeild.

Hope i helped.

Gate