The cut-flower-method of depleting a plant's internal reserves of mineral nutrients work wonders for improving flavour, colour and nose of cannabis buds.
Do just like you do with cut-flowers from the florist, but change the water in the vase everyday.
Simply cut a mature cannabis plant, right at the soil line, then keep it in the grow room with its cut stem in a big bucket of water for 5 - 10 days. Under lights and in dry air it will still transpire, but much faster and you will see the plant use many times more water compared to when it had roots still attached. It will rapidly ripen, change colours and starve itself. Cut flowers can live up to 2 weeks if you change the water often, and cannabis will do the same.
The cut MJ plant will suck up water by capillary action much faster than when it had roots, and if left under lights it will try to continue to grow, but will not receive any mineral nutrients from its stores in the roots. This could be a whole new pre-harvest handling method; imagine treating a whole crop this way, where you have water troughs to hold the cut plants for the last week of growth.!
Minerals are stored throughout the body of the plant, nitrogen especially is stored as amino acids and "storage protein" in the roots. Other minerals in the shoots are moved around as needed and are directed to the top-priority growing sites, so the whole living plant is a reserve of nutrients which we want to deplete as the plants reach peak ripeness.
Instead of "flushing" we should say that nutrient concentrations in the plant tissues need to be "diluted by growth"; meaning that during the expansion of cells and new cell divisions that enlarge the body of the plant, the plant will dilute its internal reserves, simply by having gotten bigger. We want the last increase in volume of plant tissue to occur without any more minerals being taken up by roots.