Boy, do I understand.

I have the same problem in my cat pen. My neighbors haven't complained yet, but I can't open windows on that side of the house. I've been covering some of the more obvious areas with Arm & Hammer litter deodorant, but it only works for a little while. Your area would be impossible to do that way.

Short of paving, I haven't been able to come up with a cure.

My daughter has mint growing all over in her yard. It spreads fast. I might try that. At least it smells good.

I'll be watching for some suggestions. Surely someone can help us both.

Mary