Yea, that would be my angle on it since i dont know of and havent read/seen/heard of any way to successfully flush your plants if theyre in the ground without getting screwed in one way or another.

And flushing is something you want to do while your plant is still in a stage of growth, one week from harvest, its hardly gonna make a difference.

P.S. Im hoping you get a 2nd 3rd and even 4th opinion from other more informed/experienced growers before taking any action.