Grandpa Chuck wrote:
On Sat, 1 Mar 2008 09:39:52 -0500, "Joseph Meehan"
wrote:

Are the senior citizen cats? Some times it is a physical
problem. You may want to check with your vet it could be a sign of
a problem. On the other hand it may be necessary to clean to box
more often.

They have been doing this for a very long time.
We have tried several solutions and nothing has stopped it.
I am wondering if we paint the surfaces with a sealing paint such as
Kiltz if that might seal in the odor so they no longer smell it.

If money is no object, try Litter Robot

http://www.litter-robot.com/