Tea: If you don't like coffee, you can use tea bags instead. Just place 2-3 tea bags inside the confined space. The tea leaves in the bags will not only absorb the trash can smell but will also release the natural aroma of tea.
The automatic model is sensor controlled and has a lid which quickly opens when the trash bag gets about 10 inches and 130 degree angles from the can's sensor. With normal usage, the power will last about 6 months with 4 D-size batteries. For those that do not require trash bags, the inner bucket can be easily removed and cleaned when the trash is removed and taken out.