Whethert 'flushing is a myth' or not, if you want to stop feeding there will be enough build up of nutrient within the soil and within the fan leaves of the plant to comfortably last 1 to 2 weeks.
Saves you time and feed.
But you'd probably want to be closer to done than this
Most manufacturers recommend the last week to be just water. I would take their advice, first and foremost