“Another rust-prevention tip: Store cleaned shovels, hoes and other digging tools in a five-pound bucket filled with builders’ sand and a quart of oil. The oily, grainy solution will help prolong your tools’ life.”
I’d bet the EPA could and would fine you about 50 gross worth of shovels for this practice, possibly big time, if they found you spilled this on the ground. Sorry, not very smart.
There are lots of types of oils.