Flush ? I just run plain water top off for the last week or two in DWC. Not a flush by why waste nutrients that the plant won’t take up anyway. Everything you need is either in the plant or your medium. Don’t wash it away or take it. Just use plain water to keep them chugging along.
100 growers will give you 100 opinions on how to finish a plant. Seems to be where a lot of anecdotal hypothetical scientific proofs suddenly start to cause great controversy. Leaving it alone but keeping it healthy always seemed to make sense to me. Plenty of time to try flushing, stabbing, leaving alone in the dark etc, etc, etc,etc .................
FB