The centobites are either users of the box or anyone that got in hells way. I get that. So why does Pinhead tell all the people that open the box that they are in for an eternity of hell when he just turns them into centobites to have a good time with the next victims? Do they just get to take a break from their eternal torture to do Pinheads bidding then have to go back to the rack? Pinhead doesn't have pockets, at least he doesn't appear to have pockets, so he must just remember who is up next. Maybe he has a clip board back in hell that tells him how is ready. The best, and most likely answer I believe is that he has one chain that hangs on to the list. When he needs a reminder it just shoots out then retracts. That would be sweet, but in all seriousness how is their time determined?