I got some dissolvable filament for my Replicator 2X, and have been really impressed with the results. I created a model of a complicated re-bar joint for a friend who works for a structural engineering firm. It would have been absolutely impossible to print without the dissolvable filament. I've uploaded a picture, and have a detailed blog post available at http://www.tesseract-design.com/subt...facturing.html
Fun with Dissolvable Filament
You own two 3D printers?