Re: Cleaning Solvents...a thing of the past. *LINK*

Oakite is a cleaning solvent that was used by the Southern Pacific (and the Pacific Electric) for cleaning passenger cars. The story is that it was apparently caustic and would seep into the wood filler pieces around the carlines and window sashes. The wood and the adjacent metal would deteriorate because of the caustic action. Many of the window posts on the PE cars had add-on covers at the bottoms to cover the rusted out window posts. [The Los Angeles Railway cars did not have this problem as that company used simple soapy water to clean its cars.]
By the way, I'm told that the New York Subway shops at Conney Island had a dip tank that would take motor car trucks two-deep.
I found that the Oakite company was still around; it may have appropriate cleaners. Its website has a section on fleet cleaning and under that railroads. See link below.
Brian Norden