If you can repeat this effect with a negative you can sacrifice, you might try bleaching out the silver with Farmer's reducer. I don't know for sure if this will tell you anything with Pyrocat, but with PMK it will leave the stain image which you can actually print on grade 3 or 4 paper. It might be, I suppose, that the stain is there but not the usual color.(posted 8308 days ago)