Just routine cleaning. We scrub the PFs with detergent and scotchbrite at the end of every day. Catia the manager did them yesterday and when I lifted the basket out to dial-in this morning I got an ethereal golden glow like when they open the briefcase in Pulp Fiction. Double thorough.
@StevePeel, just seen your Insta feed, what does polishing the portafilter do to the brewing process?