Cheers (!) for the link, Francois. I haven't read the piece yet, but I did try to stain my Polaroid 125i prints in Port a while ago. Didn't do much for them and I had to re-stain in coffee. Here are the two I tried it with. The first I've shown here before, the second probably not. The whites in the second print do clearly show signs of staining from the Port.
The other thing I tried with 125i was cocoa which worked wonders with any reds in the print.