Like others suggested, don't put used motor oil on a chain, O ring, X ring or otherwise .
1. Non sealed chain, it'll just fling off, there are no properties to motor oil that will let it adhere to a chain. It'll never be there long enough to penetrate any metal particle or offer any real lubrication.
Lube a sealed chain to hold down friction between the plates and the rubber ring seals and make the seals on each pin last longer. Clean it to!
2. Used oil on sealers chains: X or O ring. after the oil has been used in and automobile or other vehicle, it becomes contaminated.(why else would you change it?)
Factors include gasoline, diesel, metal particles and the usual sludge that contains god knows what. The effects that this has on a rubber seal is detrimental at it's best performance, and will ruin any proper sealing an O or X or any ring has. (EX: the rear main rubber seals on most vehicles leak, eventually due to the motor oil not being changed ofter enough, and the contaminants tear up the seal)
THe WD 40 is a fair trick, I've done it, but it has no adhesion at all,..New motor oil, (read above) fling off.
A good lube made for high heat and revolutions is best. Motorex has three great chain lubes. The Bel Ray mentioned is also a great lube and is a popular choice in the clear formula. Repsol also make a great lube.
But remember, the old Gunk products? they had a chain lube which by chain lube standards is still used today, it contained the stickiest substance know to mankind in it, smelled horrible, (try smelling the Repsol chain lubes)
It was whale sperm, said so right there on the can! Now you know. ~