I've never heard of 'breathing chrome' but have been told by several sources over the years when using any kind of chrome polish on the exhaust to start the bike. Hold your hand on the pipes until you have to pull you hand off, shut off the bike, and then polish them with your chrome polish. Guess the chrome expands with the heat and the polish is trapped in the 'pours' if you will, when they cool down. Hey, don't know if it works but have been riding for 35+ and have had limited blue'n problems.
This would work with any chrome piece that takes on heat from the engine.
Oh, and by the way XXXFLHRCI, waxed the bumper of my '72 LS5-454 ElCamino yesterday and it looks great. Ha!