I was only doing 3 days, so the longest that a diaper would sit in the pail was 2 days and 2 nights and then when I woke up on the third morning, I would bung everything into the washer. You can smell it a bit on day 2 but there is a large spike in smell when I go to wash it. Even though the washing machine is doing its job of removing the smell from the diapers themselves, it is unleashing a lot of the smell into the air while it is doing it. Washing everyday might help with this but with having to pay for water, it would significantly curb the savings while increasing the hassle.
Maybe my washing machine is just really old? It is a top loader so there is no seal around the lid and I imagine a side loading washing machine would not smell.
I am also using a simple trash can for storage, and inside the trash can, I am storing the cloth diaper in a wet/dry storage bag made for storing cloth diapers. I am also using "Munchkin Nursery Freshners" in the diaper pail to try and reduce smell. I am going to try and fit a seal to the lid to see if I can reduce the chance of any smell getting out. I may also try to get some really cheap trash bags to put the diapers in rather than using the wet/dry bag as that bag doesn't prevent smell or liquids very well.