I would have everyone drink before entering both spheres, exactly six cups.
Shimizu puts on the basilisk cloak. We go to the torture chamber, everyone drinks coffee (except Castor, but he doesn't even go into the room), then
I stand close, Livia stands further away, and you stand even further away (right by the door). And not in a straight line.
This is assuming that the empty spheres in the torture chamber don't fit the pedestals. If they do fit, or at least seem to, I would try to take an empty sphere and carefully replace it with the sphere in the room. But that's unlikely.

