Well, it is certainly easier to do with magnets than the solution I have used when needed, which is to use Cinema4D to edit the hell out of the mesh and build another piece of clothing based on that. Traveler has a set of basic magnets on his morphworld site, and yes, you will need multiple magnets in most cases. I have used something like six in some cases. Despite how difficult this seems I can assure you it is almost always easier than reworking the mesh in an editor.