A filter will be required for all those mucky and greasy wet items you want to dispose of. If you are allowed to dig into the ground at your site, make yourself a trench a just bigger than your can, and at least 30cm deep. Stuff your oil can with grass, leaves and bracken.
Place a grid (either metal or make a lattice from natural materials) over the hole and place the filter on top. Make sure you replace the filter materials often.
Use to filter any wet, or more useful, greasy waste.