The Xone:DX does have RCA inputs which you could use with CDJs, but it should be noted that a few conditions will need to be met for them to function as one would expect on an analogue mixer.
Being a control surface and audio interface, the Xone:DX requires that you have a computer attached and are running an application such as Itch, Traktor, or Ableton Live.
The audio signal from the RCA inputs will be routed through the DX's soundcard into the application, where all level control, EQ, etc. will take place, then back out through the soundcard to the DX's main outputs.
If you move from a computer-based solution such as Itch, Traktor, or Live to CDs, you will be losing the benefits that the applications offer:
- Database organization of your music
- Non-linear playback
- Easy setting of cue points
- Beat sync
With CDs, you'll be limited to a linear playback format, and be at the mercy of the disc player's feature set at the venue.
Hope this helps.