She also has told me the magnets have to be really strong - not the kind you get from "pyramid schemes" and just as important is where they are placed. You can do more harm than good if you don't place them correctly! She has to place them at two points on the body - for my shoulder one is in that area and one at the bottom of my foot - she needs to do some pressure point feeling etc. then decides the best points for them... then she continues to work on other techniques while she leaves the magnets on. Total time 1.5 hours each session.
I have had people approach me with the pyramid-scheme magnet idea -almost went to a group meeting one night until I found out what it really was about... stay clear of those people trying to sell you into selling etc, etc!!
As I said the ones my therapist uses are really strong - she has to be careful to keep them separated, and she can't always hold them apart - if they get within say a 1 1/2" or so apart they spring her hands together with a lot of force... I'll ask her the strength next time. Also, she has not used them for my PF only now since my shoulder problem and sometimes for my lower back.