Hi, I'm not sure why this post is being bumped from a year ago?
But I'm wondering why the ::cck:: removal is necessary? why is your introtext field being used as the meta description?
I think a better approach would be to use the SD Concat plugin (on the store), set up with the correct storage for the core Joomla meta description field (Standard > Article > metadesc) to duplicate your introtext content and store it in the correct place. Then there will be no ::cck:: tags, as they are only used to create the links between the cck_store_form tables and the com_content table.
_jrmo