I tried this procedure on old Eastman 16mm print film that has gone red. My friend provided the sample.
Didn't work on this film .
The test procedure was;
Presoak for ~1 min
K ferricyanide 50 g/l for ~10 min
Wash with running water for ~3 min
Re-develop with Rodinal (1+10 for ~2 min) (Because ferricyanide bleaches the optical (silver) sound track away.)
Wash with running water for ~5 min
Stabilize with Jobo "3-bath E6 stabilizer" (with formalin), double strength for ~2 min.
This process that was suggested was provided as a shot in the dark [pun intended] to save the transparency.
Warning!! Handling a Hasselblad can be harmful to your financial well being!
Nothing beats a great piece of glass!
I leave the digital work for the urologists and proctologists.