You probably won't get the grime off that plate tank. The plating on those is not nearly as robust as the round film tanks which came along later. Aggie is right about just cleaning off the grime with soap and leave alone.
The ironic thing about the wood "tank" you have is that it is not really a tank but simply a box used to wind roll film on an apron which is then transferred into one of the round film tanks you have. The film tanks could use aprons for roll film or a metal holder for several pieces of sheet film.