Hello!
My first take after a dark wash, would probaly be... white! this way you can show some clean spots on a dirty wheel bay. Some silver might wor, too. But I'm not too sure if you need that dry brushing. A nice dark wash is usually enough. Look at wht you have - if you think it looks right don't do anything more to it just because someone wrote something in an article...
Here's my 1/72 whale gear door - I addes some detail there, then painted it white and made a wash. I didn't feel like doing anything more...
Good luck with your builds and have a nice day
Paweł