There will be real pain. The source of the pain will be more than likely psychological and will be a result of the cleansing. As opposed to a pain inflicted just for the heck of it.
SD
For something you are so sure of, it's amazing you have to guess at it. Where's the scripture for this? Oh, right, this is truly one of those make it up as you go type doctrines. Shh. Don't tell....