Bike Oil Alternative?

When I run out of bike lubricant I might use what I have around the house. Recently I experimented with Marvel's Mystery Oil. I filled Grandpa's Oil Can with the red stuff, after my dad's praises - besides, he'd given me a bottle. I'd used it on the brakes and derailleur, but never the chain until now.

For a while it seemed to work. No more squeaks and groans...or so I thought. But gradually the pedaling felt rough under my feet and worsened  until the chain was literally grinding over the cogs.

At first I thought the year-old chain needed replacement, but after measuring links I determined that wasn't the cause. I borrowed a bit of my husband's bike oil and applied it in place of the Mystery Oil. After wiping the chain and pedaling a few laps of the neighborhood, the problem cleared up - just like that.

I learned my lesson: always use specific bicycle lubricant. But this irks me, in a way, because a bike is a machine and there must be a multipurpose oil that could replace those expensive small bottles, only found at a bike store.

In a pinch I've used motor oil on a chain, but it was a one time event - I have no idea how this stuff works over the long haul.

What kind of lubricant do you use?