Used motor oil ??

Well, I either change my oil at the fire station shop and leave it there, or I store it up in a 30 gallon barrel that I list on CL for free and have someone pick it up (reminds me I need my barrel back). I have also been known to take it to the parts store if need be.
I've seen it used on the dirt floors in barns to help pack down the dirt and keep the dust down.