My preference is caustic soda solution. Takes 'chrome' and varnish off in about 5 to 10 minutes, occasionaly and rarely perhaps 20 minutes max.
My friend from Australia uses this. He said he starts with flakes and mixes the solution. He was telling me that he tried to get CSC since he saw it on the board. He either wanted to know where to buy it, or what the active ingredients were and what would be the Aussie equivalent. So he called up Castrol in Australia and the folks there hadn't heard of it. The guy called him back and said no, it wasn't available, and that nothing that caustic would be allowed to be sold in Australia!