btw...how was it that your cats could have used your entertainment center
for a year???

Ah... ask and you will learn. On the opposite side of the wall from the
entertainment center is an unfinished utility room where we kept the cat
litter boxes. A nice big room with the washer dryer and all. Excellent for
storage. I built these really sturdy shelves out of 2x4s and plywood, one
of the best things I've done to the house. The cat used them to climb up
and lay on the heating ductwork. Didn't bother me, a nice warm place to
rest. The the cat had peed on the carpet before and the litter boxes being
in the other room and all we figured that the odor was just the normal pet
odor you get from having a cat. The smell got a lot stronger and I started
investigating and found that the cat had access to the ceiling cavity. It
was a mess, which has been pretty much cleaned up. Only way I can see in
the cavity is to take a picture of it with a camera.

I can saturate the cavity very well with a garden sprayer. I'll try the KO
and hope for the best. It's the last thing I'm trying before I seal up the
wall and finish the room.

Thanks!
Tom