"Errata to previous, for parts in general.!!"
Why have you changed your mind?
Should be careful that the solution does not eat aluminium and magnesium components in the engine.
For parts and entire car panels in restorations:
I use diluted vinegar in a large tank. The tank is simply concrete besser blocks forming the 4 sides and lined with builders plastic. Also covered with builders plastic to reduce evaporation. Fully submerged for 24 hours removed and then water blasted with a small water blaster bought from the hardware. The guy in the video does it the hard way and scrubs the wheel. The water blaster is faster, and does a much more complete job by getting into all the nooks and crannies. Best of all the vinegar can be reused indefinitely over and over.
Care must be made if leaving the component in the acid PARTLY submerged for more than 24 hours. The acid WILL chew into the zinc coating and the steel itself on car panels at the top of the water line. Best just to move the component around or flip it over every 24 hours if the rust is very heavy. I have a policy to remove the component after 24 hours, water blast it, and if all the rust has not been removed put it back into the tank but in a different position to where it originally sat.
The molasses takes too long and stinks. If you like salt and vinegar chips you will like working with the vinegar. Remember it is an acid so handle with good rubber gloves and eye protection against splashing.
Clothes will turn brown if splashed. It WILL chew out concrete if allowed to sit. So have the tank on grass or dirt just in case there are pin holes in the builders plastic.
It does work!