Don't you think it is kind of strange that you filled the gas tank with oil... but drained the oil tank and leave it empty?
Anyway... besides that... I know a lot of farmers take used motor oil and soak rags in it and then wipe down all the sheet metal to prevent rust on it (they lay it on thick too)... and they found that the used oil sticks better to the sheet metal than brand new oil.
Drain the carb float bowls too.
Squirt some oil in the spark plug hole.
But you ought to sell some of these to kids who could use them.