Quote Originally Posted by Gerald C Koch View Post
Manganese dioxide should not form if the bleach is used properly. It is important that the bleach is acidic and then the permanganate will be reduced all the way to Mn+3.
This happened in another test I was doing, it was certainly acidic, but it wasn't sulphuric acid, it was acetic acid.

Quote Originally Posted by Gerald C Koch View Post
The only bleach that I have had trouble with is the copper one which caused severe softening and frilling of the emulsion
Haven't had that, have only ever had trouble with permanganate + bisulphate and sulphuric acid bleaches. I haven't tried the CuSO4 + H2SO4, as that seems unlikely to work.