I've never finished with the FoxFarm stuff but if you have already been feeding lightly, I would flush heavily today, use only molasses from here out, water to runoff every watering, and chop as soon as you see evidence that the lower leaves are using up N and becoming yellow. Or flush heavily today, wait 2-4 days, and then just take em down.
This may not be standard procedure but since you say you are already 'ripe', that's what I would do if those were my plants.