I have been working on .ssh files for years and haven't found a solution. They are in most PS2 EA Sports games, and are like .fsh files except they are compressed somehow. The farthest I ever got was to view an unswizzled image of a .ssh file by using the fsh editor.
Over at mvpmods.com and planetcricket.net there are many forum posts about these .ssh files.
Another way to run edited ps2 games is to rebuild it back into an .iso with a program called CDGENPS2, inject it into a harddrive with a program called WINHIIP and run it off the harddrive with the program HD Loader.