Are you sure that using swiften is a good idea?
1. It does not support simultaneous connections to several accounts.
Actually there was a question about that in swift mailing list and the answer was that: "Noted, thanks - it’s on the list and Daniel (one of our GSoC students) is looking at this over the summer." However the summer was the 2015 one...
2. It does not support XEP-0313: Message Archive Management. Can't imagine a multiuser chat where you see only those messages when you are present...

The best one is probably Conversations (android) and in the Linux desktop area Gajim (pygtk). Also Psi (qt5) says that XEP-0313 will be supported in version 2.0 (currently 1.3).