heavy carbon on valves, what to use?

When I had my carbs off to clean them, I saw a lot of carbon buildup on the valves, I sprayed some carb cleaner down there, and put some lucas oil gas treatment in the tank (and gave it a couple Italian tune-ups). Is there anything else that's recommended? octane booster for a tank or so, or some other additive to heat that crap up?

I use Sea Foam.  It's supposed to be magic.