I have reused my soil so much and added organic amendments that all I can feed is carb boosters for most of the grow without burning...everything is perfect as long as I don't mess with it...lol.
but I have never purposefully flushed except when I was new and thought everything was something wrong...I don't flush at all now usually, but I always water til run off whether in soil or coco..I recently started using coco since my soil doesn't need me anymore...anyway back on topic...
You do what you do, And I do what I do...
I don't flush, and my buds taste great and burn great.
Except I can say that I have been overdoing the carb boosters on my last run..it made the buds too sticky...they are difficult to work with even after drying and curing..they gum up the jars and my grinder, scissors, hands..whatever they touch..