Carb. Cleaner will do its best to remove any paint as well.
For diesels WD 40 can also be a combustible, be very, very careful using it.
There are products, magic bright, gunk, meguier make them to name a few.
They don't work as quickly, but give them time, and multiple applications and you'll be eating off the manifold soon enough.
We are not primarily on earth to see through one another, but to see one another through
Some people are like slinkies: not really good for anything... but you can't help laughing when you push them down the stairs