KODAK S-13 STAIN REMOVER
Part A:
2.5 g Potassium Permanganate
8 mL Sulfuric Acid or 24 g Sodium Bisulfate
One litre water
Part B:
10 g Sodium Bisulfite
One litre water
Don't mix the two together. Immerse the plate for one minute in Part A, then one minute in Part B, followed by a five to ten minute wash. The sodium bisulfite gives off quite a strong effluvia, respirators mandatory. It will remove the pyrogallol or pyrocatechol stain from holograms, or most any stain in the holographic darkroom's trays.
These baths can also be used as a reversal bleach, but they are temperamental.
Bleaching time: One and a half times the time it takes to clear if used as a reversal bleach.
Temperature: 20C Agitation: Intermittent
Shelf life: This stock solution lasts practically indefinitely.