This is going to sound funny, but I found this product called Fresh Drops and it's the best invention ever! You put it in the toilet and it helps eliminate the odor of extended visits. DH can leave a bathroom smelling so bad that you don't want to go anywhere near it for a really long time, and this makes it so much more bearable! It's the little things in life that make things better.

http://www.amazon.com/Fresh-Drop-Bathrooom-Preventor-67-Fluid/dp/B0011UWNO4