We have been on the bucket for seven years, and there is six of us. We have literally never had an issue with smell with either of the two bathrooms in the house. We have compartments that hold two buckets, and when the two buckets become full of both pee and poo (and shavings), then they go outside and are replaced with two more buckets. When I have ten full buckets (once a week) I open the pile and dump them. Here is a link to a video of the dumping
We also do a lot of research and policy work around such things, and have been able to legalize the bucket system, and have even built one at a local regional park, where we also service them. Neighbours bring their friends by just to look at the bathroom... and again no smell. The research and analysis on the compost allows us to safely ensure we can use the composted materilas on the food gardens, as well as hen I do a presentation to schoolkids or engineers, I can let them handle and smell the compost.
One key point, if you remove the urine from the bucket, you are removing the nitrogen from the system, and the composting process is less vigorous and the end product is nitrogen deficient (as studied at UBC Choi toilets that do separate). The course we teach on grey water and composting toilets has one common point... if it smells then your doing wrong - neither should ever smell.
In our home we run a 24VDC 50cfm fan which keeps the slightest of air flows through the toilet compartment - this also seconds as the bathroom exhaust fan, as well as services the whole house's demands under the building code to meet the required air changes per hour. Don't be nervous... trust what Joe Jenkins has written... everything goes into the bucket and give it plenty of cover material, more if it seems sloppy. My fovorite time of the year is when I dig into my 2 year old pile and place it in the gardens. All exciting!