Hey guys. I'm working on a cylinder head off of a generator and had a stuck exhaust valve which I got fixed but there are tons of carbon deposits on piston and inside exhaust valve chamber and around spark plug. I've got most of it off but there is still quite a bit. What is the best thing I can use to clean this junk off? And do I need to get every bit of it out? Thought about brake or carb cleaner but will that damage the oil seal on the intake valve guide if it gets on it as it doesn't seem to be removable? I've also got small wire brushes that are copper and brass but I dont want to damage anything in the cleaning process such as the mating surface for head gasket. Any help would be greatly appreciated!