I believe that you can use RX with Amsoil in the cleaning stage but it may not be as effective, however, dino MUST be used in the rinse cycle. As to the maint dose and synthetic, I believe Frank wishes one to use dino if you are using RX for maint however, I do not believe it will do any harm with synthetic. For seal seepage I believe Dino and maint is the suggestion after the initial cleaning/rinse cycles