Best cleaning product to get exhaust residue off RC Planes?

I'm new to r/c plane flying. I started the engine for the first time, and was surprised how much oily exhaust residue builds up down the side of the plane, on the landing gear etc.

What is the best cleaning product to get the oil off, without damaging the MonoKote covering?

You can use almost any window cleaner. Try to stay away from products containing ammonia. It can dull the Monokote after awhile.