Here is system all others have failed to clean claiming they cannot effectively remove wok style grease. Here are pictures of section of a system just cleaned 2 weeks ago before, during, and after a proper cleaning. All it took was time, elbow grease, and the proper equipment. You can see that the years of buildup can be removed effectively and the system is now clean to NFPA96. Sorry I am posting one of our own jobs, we have to show off once in a while!!