In London I can remember Shri Mataji getting someone who had been to a false guru to cut up a lemon into smaller and smaller pieces. It really did seem to help him afterwards. I cannot remember if he held it previously or what. As for which hand to put a lemon in, I feel that one has to just see which hand it works in, Shri Mataji would sometimes change things. For example we were told very early on to put our left hand to Shri Mataji’s photo and right hand to the candle and also, if the left side was catching, to raise left to right. After some time it changed to raising right to left, and the left hand towards the candle.
John Watkinson