I'm going to go and do some more reading. I want to hear again what exactly Andreas has said about this. It makes good sense to me to use fresh oil, if doing longer than five minutes. If memory serves, he has said that after five minutes the oil isn't actually absorbing much -- that it's saturated, so maybe it's in some ways wasted time, if not actually 'toxic' per se. I do know he feels OP is a very good thing to do.