Jordan, that's me (the poster) and...
Originally Posted by htmlguru4242
...yes I found the Copper sulfate bleach completely a failure on my part.
I would recommend the permanganate based bleach or, if you dare, even the dichromate based bleach (more toxic - take care of yourself).
Which one of the two you decide, based on quantities, costs, toxicity and prompt availability.
I can say that dichromate is the most reliable in terms of negative integrity, second comes the permanganate but I think, if all solutions are kept at THE EXACT TEMPERATURE, avoiding even the slightest drift, and if the films is GENTLY agitated in the permanganate (even better would be a dip-and-dunk style of agitation), even the latter would do.
The drawback with the permanganate is that it softens the gelatine more than the dichromate, which tends to tan it.
Maybe a hardener pre-bath can help.