They are harvestable in my opinion, so just give them plain water for the next waterings. Flushing is not as vital in soil, it is more of a concern in hydro with chemical/mineral based nutrients. In soil you are pretty safe. In future, if you are concerned about flushing, just give your plants plain water for the last 7-10 days before harvest as a good way to "flush" your plants.
Hope this helps,....... Organoman.