EGR valves can be cleaned with anything that will soften and remove carbon. One of the best is the Ford Combustion Chamber and Choke Cleaner. Most dealers carry it in either liquid or spray. Most any carb cleaning spray, choke cleaner, or throttle body cleaner will work somewhat.
Personally, I've never had much luck with cleaning an EGR valve. If it is sticking and binding it will usually need to be replaced. I guess it would't hurt to try before spending the money on a new one.
