How can I enforce the use of factory methods on a strongly typed DataSet?

Question

Without breaking the VS2008 designer, can I set my DataTable.New*Row methods internal while leaving the overall DataSet and its tables and classes public?

I'm using the VS2008 designer to create an ADO.NET strongly typed DataSet for my application. Some columns refer to external tables. I'd like to check those references at creation time.

The Factory pattern seems to be an obvious winner, here, but I'm not sure how to enforce its use without nasty side-effects. If I set the DataSet's Modifier property internal, which VS2008 applies to all the classes it generates, I suspect my users' classes won't be able to refer to the DataRow descendants at all.

I've tried searching for answers to this one on Google, but all I pull up are articles on ADO.NET Database Provider Factory classes.