ERG/Brake Cleaner. As posted elsewhere on this thread, small wire brushes and picks. Set piston to TDC (spark plugs removed) spray the cleaner in and let it soak for 10 to 20 minutes. Wire brush, pick/scrape heavier deposits, then mop out chamber with rag strips. Repeat as necessary until clean, then repeat process with each cylinder. When valves were open I also cleaned around the rim with dry cloth strips.
Roadster 3.7 Plus 4 110 Anniversary Plus 4 Fiat TC