'Extra Fine' or 'Fine' wire wool and tooth brushes for awkward nooks and crannies, with an initial dose of drain cleaner to shift the muck and baked on crud. WEAR PROTECTIVE GLOVES, GLASSES OR A FACE SHIELD AND OUT IN THE OPEN AIR, HCl CAN HAVE AN ADVERSE EFFECT ON YOUR LUNGS!
A thorough flush, dry and then buff using 'Extra Fine' wire wool and 'Autosol' or 'AutoGlym' metal polish. Then polish.
I prefer to use elbow grease rather than drills, mops etc. I can get in the fiddly bits and don't have 'missiles' fleeing about the workshop!
Whilst Sally's silencer has a 'ding' in it, it is still structuraly sound and I think will be re-fitted, having been given this treatment and coming up a treat.
My regards, Bill