I made a somewhat successful attempt at reducing dead space in my system. I have false bottoms in the mash/lauter tun and boil kettle. I went to a craft store and found "flattend" clear marbles to fill in some of the space. These are the things that your wife or GF might put strategically in a bowl on the coffee table. I suppose you could borrow them if that is the case.
I found that the marbles also help reduce hot break as well.