PreHarvest Flush, 3 times water or just regular PH water?

2 week preharvest flush ? think your reading to much stuff. I grow in coco and do a 4 day flush and it works out awesome... even a dry 2 day flush makes smooth bud at least in rock wool and coco.. 2 week flush seems nuts to me. ps for the flush I just use tap water with no ph fix, now when growing I check my PH like every time I water but not for flushing.