I’ve been bored the last few days so I decided to go on a little car detail Extravaganz. I cleaned everything I can think of but I’m stuck on two areas. The control arms and the subframe in the engine compartment. Just can’t seem to get it to look clean. I don’t want to start putting crazy chemicals on them so I searched the forum and couldn’t find an answer. What’s a good way to get it to clean up?