It seems to me that you could accomplish the same as Extrude Hone with a wet sand blasting set up.
I can't remember the name now,
but I am pretty sure I had a small electric pressure washer (German ?) in the 1980s that came stock with a nozzle that would suck in sand and blast it out with the high pressure water.
a quick Google search found this:
http://www.pressureparts.com/None-C-SandBlas-Pressure-Part-391510.aspxI admit that it would be hard to get even an extra long shank carbide burr inside some of the exhaust manifold passages but the wet sand blast nozzle should work