I started a rust stopping thread a little while back and people were talking about oil sprays. I would like to know what kind of oil is used and where/how it is applied.

 

They spray it in your body panels and on other spots. They'll likely drill small holes in certain parts of the car and spray oil in. They'll fill in the hole with a rubber plug.

The "kind" of oil they use depends on the organization. eg. Both Krown and Rust Check have different oil mixtures which they apply. eg. Krown's mixture drips very little and doesn't collect a lot of dirt and it seems to "creep" over time (meaning it gets into all the little spots).