The potassium salts rinse off when you quench.  I have a metronome app on my iPhone and set it for 60 beats per minute.  The first "beat" is a higher frequency than the following 3 so I set the case in the holder on that one.  I set the temp for 1000F and leave the case in the bath for 4 seconds.  The heat transfer from the liquid salt bath is consistent and efficient.  The case holder sets them at the correct height in the bath.  It has places for two cases but I only do one at a time.  I can anneal 200 cases in 30 minutes or less and every one looks exactly the same.  I know there are folks achieving great results with a flame but there is no learning curve with this method.  Just remember you are dealing with a 1000F liquid; safety is paramount.  I clamp my lead pot to my bench, wear clothing appropriate for welding, long leather gloves and a face shield.  Had someone not shown me this method I would have never undertaken annealing.  I used to give my 10x cases away to a friend who annealed (sorry, lol >:().