How do you melt colors on a photo print?

If you haven’t seen it, Nick Knight did an amazing series where he used chemicals, heat, and water to make the colors on his prints drip and warp like this http://arpeggia.tumblr.com/tagged/nick-knight. I’ve looked everywhere to find his exact process, as well as sent an email, but I was wondering if any of you knew how I could achieve the same effect.