I have found that lubing the interior of the Kroll with a conductive lube has avoided me of all the talked about Kroll problems. I have yet to have a single problem on any of my 5 - 6 lights that use the Kroll.
I use a toothpick and lightly coat as much of the metal springs and parts as I can reach. No lube on the Kroll threads. I use conductive lube on the LS battery threads after thoroughly cleaning them and just a touch on the positive battery end. I redo the threads (clean and lube) every 3 - 6 months or when I think I need to. I add to the Kroll battery spring at the same time, but other than that, I haven't opened up the Kroll since I first treated it. I clean and relube my AAAs more often. I used to use a different lube on the O rings, but not anymore. Remember that the lube attracts dirt and debris so be careful.