Several threads refer to kodak publication AE-31 for dealing with kodachrome and ektachrome developed as B&W. Just for the record, here's the section of that publication that deals with removing the Orange Stain:
To remove the stain from KODACHROME and KODAK EKTACHROME Films:
1. Prepare the bleach bath by dissolving 1 ounce (28 g) of KODAK Citric Acid (Anhydrous) in 1 gallon (4 L) of KODAK Rapid Fixer diluted as recommended for films in the fixer instructions.
2. Handle only one negative at a time. Treat the negative in KODAK PHOTO-FLO Solution at 75-80°F (24-27°C) for 1 minute. Use fresh solution prepared as directed on the label.
3. Rinse in water at 75-80°F for 20 seconds.
4. Immerse in the bleach bath (prepared in step 1) at 75-80°F for 7-14 minutes.
Stop bleaching if reduction of the silver image becomes apparent. It is better to leave a little stain than to lose the silver image.
5. Wash the negative thoroughly in running water at 75-80°F for 10 minutes.
6. Remove water droplets with a soft, viscose sponge. or treat the film with KODAK PHOTO-FLO Solution for 1 minute. Dry the negative.
Print the negative as you would any normal black-and-white negative.