Is it possible to obtain full-text contents of documents indexed by WDS through query interfaces?

Is it possible to obtain full-text contents of documents indexed by WDS through query interfaces

As far as I know, there is a special system property System.Search.Contents, which represents textual contents of the indexed document. But MSDN states:

System.Search.Contents: The contents of the item. This property is for query restrictions only; it cannot be retrieved in a query result. The Indexing Service friendly name is 'contents'.

And contents of this column in query result datasets seems to be DBNull indeed in all cases.

I would like to add some kind of post-processing for all documents, processed by WDS. In order to do this, I need to access full-text content of the documents being indexed. As far as I understand, the most efficient way would be to extract text directly from WDS index, if possible. Are there any WDS developers here Does WDS store full-text contents of the indexed documents internally Is it possible to retrieve that text somehow

I have also considered running IFilter once more for each indexed document on my own, but I stumbled into problems with e-mail (and presumably all other types of content, which is not directly accessible through the file system). There is a property System.ItemURL in WDS, which identifies indexed document. Theoretically I should be able to obtain item text by creating proper IFilter for that item using LoadIFilter or BindIFilterFromStream, but I cannot figure out how to create IFilters for non-filesystem objects. Is it possible to obtain IStream interface somehow from ItemURL like this:

"mapi://{S-1-5-21-641218907-4187178781-2627367884-1105}/Personal Folders($b697f890)/Inbox/..."