Im not sure that I agree. If its a slow release fertilizer, which it likely is, flushing it all out or most of it could be difficult and it might need so much flushing as to cause an over watering problem.
Either flushing or repotting is taking a risk of one sort or another or some degree of risk or another so I guess it comes down to what is considered to be the lesser of two evils.
Myself I would most likely do a bare root repot. Id take it out of the soil and rinse off all the soil from the roots and then repot in totally new unfertilized soil.
My family owns a nursery, as in trees and bushes and not as in plants or taking care of kids, and now and then we will have crews fertilizing and since it covers many acres, its a pot in pot growing system, at times there will be some overlap where one crew will fertilize part of a row or an entire row that another crew had already fertilized and when the burn is spotted normally a bare root repotting is what is done and it always works and while his plant is stressed already if the types of trees and bushes we deal with can stand the stress a pot plant that is tougher than those sorts of things when it comes to handling bad conditions and stresses should be fine and should respond in a positive way very soon afterwards but that is only my opinion based on what we do with other things so dont take it to the bank or anything.
Once shes healthy she'll explode with new growth. I personally love to veg under cfls anf flower under hps.
