I don't think the Patriarch of Constantinople manufacturers chrism "exclusively" for all the autocephalous churches. I believe each does it for the churches under their jurisdiction. Wsk 21:16, January 23, 2009 (UTC)
It is not entirely clear. I was always under the impression that either it was produced for every single one of them there; or at least to not just those churches under the Patriarchate, but the other Greek churches, including the other ancient Patriarchates, and Cyprus, Greece, and Albania
Eugene 21:43, January 23, 2009 (UTC)
Here it has a reference from Wikipedia but I can't be bothered to locate the relevant text; it's there somewhere. In tha past all the chrism in the world was produced there; today perhaps the autocephalous churches make their own.
http://en.wikipedia.org/wiki/Church_of_St_George,_Istanbul#cite_note-1 Eugene 21:50, January 23, 2009 (UTC)