Cleaning the inside of chasis

[DORIGTT]

Unfortunately, the only method I know of is to have it chemically dipped/stripped.

Due to the confines and the fact that it is several feet long, reaching your hand with a solvent soaked rag inside to clean isn't a good option.

Or...get a bunch of Smurfs with flashlights and mini power-washers!
(Did I just show how cronologically advanced I am with the Smurf thing??)