Interesting finding about using potassium chloride versus the tea tree oil or bayer dips:I use Potassium Chloride. 2 Tablespoons per gallon
Potassium chloride actually KILLS aefw. They shrivel up. The other stuff stuns and dislodges but they stay alive merrily cruising around the bottom and sides of the dip tray many hours later.
I had one small milli colony that did not like the dip and has largely bleached. It was already ailing for some reason. Just 1 of roughly 100. Similar loss rate to my other dips.
I appreciate the tip @shane backer; I'd never heard about potassium chloride for this purpose. Its cheap, seemingly effective, seems safe, easier to use than Bayer, and no harsher than melaleuca oil.