In the past, when I was servicing diesel gensets for a living, I made an attachment or the hydraulic press and would squeeze oil from the filters and use it in our waste oil heater in the shop. Back then, I didn't want all that oil in the landfills.
Some of the Cat filters were about the same size as a roll of paper towels. I'd get almost five gallons of waste oil at the end of the day. Wish this service was available back then.