Hi, i agree with Grey_wolf. Personally I find that IF you didn't overnute them during their life there is no need to flush it. And from what I understood, even if you flush, you're not going to get out the excess of nutrients, especially in the end of flowering. Not feeding your plant the last week of flowering is purely economical, at least in soil I find. I find that the correct drying and curing gives the weed it's smooth taste, IF you didn't overnute your plants during their life.