In the late Barry Thornton's book "The Edge of Darkness" he describes a technique he calls Drag bleaching (in the last chapter "revealing irregularities"). He immerses a fully toned (selenium) print in dilute bleach (NB! not reducer as there is no hypo present). The seleniumtoned silver resist bleaching, but as the selenium toner works from the shadows first, the highlights are least resistant to the bleach. The effect is that the bleach works on the highlights, while leaving the shadow. He warns against leaving the print too long in the bleach, as it will go too far. If it go too far, you can only redevelop as it is bleach and not reducer that has been used. Anyway, I get the impression that one actually sees how long the print should be bleached, and then washed and transferred to fix. I have tried this. My first observation was that very little happened in the bleach. When transferred to the fix, everything happened in terms of effects from the bleaching. Consulting other sources regarding bleach, it turns out thet fix act as a catalyst to the beach, and is necessary to obtain a bleaching effect (but then we are talking about permanent reduction?) What am I missing from Thornton's procedure??