Spirit, I think that the CIRCADIAN rhytm and the regenerative periods for all inner organs are to be taken into consideration. The timetable for the flush corresponds with this. We are individuals YES, and therefore react thus. However the grapefruit oliveoil is powerful, also sedating (like any other intake of exessive fat) and in order to avoid gagging it IS good to lie down....also it tends to put people to sleep. If not always then often, and I think that the process is more thourough while the body is sleeping. It is as though the amounts of esalt and the oo/grapejuice are calculated in perfect equation with the regenerative/resting schedule.
Naturally, there will be selfinvented rules and hearsays, but this one with the oo is very logical. Biochemically.
Again, this is merely my point of view.