I have some grime that has migrated to areas I would never have expected dirt to reach. Any advice on cleaning the big hunk of brass?

Duraglit wadding, be careful though as the chemical from the wadding can seep between the brass/body interface..I usually take all the brass parts off,  use the above and then rinse in warm water then buff to a shine with a microfibre cloth

Hey!  I used Brasso products for yeas when I was in the military but I never thought to use it on my bass.  
 
Thank you