Here's some more info, don't know if this brand is available in the States..?
http://www.owatrol.com/products/OwatrolOil2_pi.pdf
If anyone is having trouble finding this stuff, try asking for "Penetrol" instead. It is sold under that name in Australia and the US.
It's real good stuff. You can even mix it into primer instead of thinners to make it key into the steel much deeper.