All you are doing when you "flush" the organic soils is killing off the microbes that you have worked so hard to get right for the plants best growth conditions. IMO your are better off to amend it with the basic organic nutrients(worm castings, compost, blood bone meals etc..) and let the microbes go to work on them . That way the nutrients still left in the soil will be broken down father and those add will be broken making both available in the most usable plant form for when the plant needs it.