You can't eliminate it. The bleed-through is going to go SOMEWHERE. The trick is to engineer the situation so that the "somewhere" is a place the spectator can't see. In the middle of a room sounds like a tall order. I don't know if it'll help or not, but this is my tutorial on Hollusions. https://www.youtube.com/watch?v=pHgT49Lw8mU I start talking about bleed-through at about the 14:00 mark.