The idea is to stop feeding then N about 10 day's before you start to flush. By stopping feeding then N it will force the plant to use up stored chlorophyll and that will speed up the curing process.

Flushing with a commercial flushing product is better then just using water. They really do work and draw out unused nutrients in the plant. The flushing process takes anywhere from 3 to 5 day's if you use a commercial flushing product. It takes 10 day's if you use only water to do a proper flush.