If I may clarify: Unapproved here would typically mean engineering hasn't signed off. It does not mean engineering was asked and said "Hell no".

And additionally, using dish soap to lubricate parts for assembly is standard procedure elsewhere in many industries. It's sometimes even recommended in the standard manuals as part of a repair procedure (I've had refrigerator gaskets that call out using a bit of soap on them before installation).

A crucial difference being that there's no risk of your refrigerator gasket sending a 3 tonne metal box into a crowd of people if it comes loose, unlike the gas pedal on a truck.

Playing fast and loose with the processes surrounding something as important (and dangerous) as the gas pedal is recklessness of the highest order.