Jms, thanks for the suggestions.
I used to rinse the diapers before adding them to my diaper pail and I agree that it works. However, now I try to avoid rinsing the diapers as the diaper pail just gets too heavy for me to comfortably manage (I have back problems).
However, it has gotten much better. I keep my diaper pail (a Rubbermaid trash can) in the garage. To keep odor from building I began adding a liberal amount of baking soda with each used diaper I put in the pail. Everything, including the baking soda gets dumped into our top-loading washing machine. The baking soda seems to have had a significant effect in reducing the odor during the rinse cycle. My wife even has commented about how little odor there now is.

I usually wash diapers every three days. As I also wear cloth during part of the day, three days equals a full load.
--John