PE, do solutions like Agfa's Sistan deal with the residual silver in prints in a meaningful way?
No, the intent of these treatments is to protect the silver image from atmospheric pollutants. Traditionally a print was briefly toned in selenium or gold to achieve this protection. Their effect is negated by a poorly fixed or washed print.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.