cruizer,
You can use these to get into the internal crevasses
http://www.cratex.com/
I would also suggest that you go to a VW forum and see what grit the intake manifold should be polished to. Remember the air has got to tumble through the manifold. I know there is a recommended grit finish for carbureted engines but I can't find anything in fuel injected engines.
You can check out this site also
http://www.sa-motorsports.com/do-it-yourself.aspx
John