We have sailed on all of the Disney ships (all over the ship). We have never had a problem with dust (but I love Clorox wipes and might take them for the trip!).
First cruise we were in 10656. No issues for us.
I always bring the clorox wipes to wipe down remotes, wave phones, safe door etc. My family thinks I'm neurotic, but that's ok, lol.
We have been on the Dream (4 day) and Fantasy (7 day) and only experienced "funnel dust" on the 7 day on our 5E room balcony. Seems to be related to the longer cruises and the speed that the ship is going. Faster speed = more fuel consumed = more soot from the stacks. Not a technical explanation but this was our experience.