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.
Trash Can Smell Masking : If you can't beat them, hide them; that's the whole idea behind perfumes and some such products, isn't it? The methods below basically mask the smell with another more powerful odor rather than remove the smell, so you should be sure you are going to be happy with the result.