After cylinder head is hot tanked and dry, we have the option of Vapor Honing.  This makes the cylinder head look brand new, and is by far the best looking finish for aluminum.  This is the best way we have found to remove carbon deposits; and cylinder heads all together.  Flushing out the water jackets afterword in this process is easy to do with the setup on our machine.   We do proper compressed air blow out procedures to prevent glass bead from staying in the water cavity, along with oil galleys.  Our cabinet has compressed air, and fresh water flush for a combined advantage for removing remaining glass bead.