As for giving the body a break - that's a big reason I OP. I feel that some vital organ (probably the liver) is given a break by OPing doing some of its work for it. How do I know this? It's all subjective, but viscerally so.
I've always felt lighter and like some kind of load was taken off every since my first pull some months ago - which I know is what keeps me coming back. But it's gone a step further lately. Lately I'll wake up feeling (as I often do) congestion in my chest and heavy as if my kidneys or liver is somehow overwhelmed . Back in the day I'd take some kind of blood tonic like a strong Korean Ginseng extract which helped.
But now I wake up just with this powerful jones to start OPing, and I feel absolutely glowing for hours afterwards. Actually these incidences happen less often these days, but when they do, OPing takes care of it beautifully. It's almost as if my body's telling me "I'm getting tired of shuffling around these toxins non-stop - why don't you do that thing you do and give me a break for awhile?" I know this sounds weird, but its the best way I can explain it.