I found an idea online somewhere for using essential oils to help with the smell. The only oil I have on hand is tea tree oil. I knitted a little tag with a long string - it looks like a necklace. I hang it down inside the diaper pail and sprinkle a few drops of essential oil on it. It works so well! All we smell now is tea tree oil, so I'm thinking I want to get a nicer smelling oil.
When it's time to wash the diapers, I take the tag off the pail and give the pail a hasty wash. I usually let it dry outside overnight before I set it back up in the nursery again. I sprinkle more oil on the knitted tag, and that's that.
Other easy methods for deodorizing a diaper pail?