I looked at a Swifter not long ago and wondered about this. The soft downy filler inside it might (or might not) be okay, but the harder outer material makes me pause.
I think that even if the Swifter turned out to be paint safe, it has some shortcomings. I don't think its sweep is very even (from the one I saw) because it's up to you to put a head on and "fluff" it open. You're going to have to press down a bit to get even coverage. Also, it's a bit smaller, so it will take more passes.
CCDs last a very, very long time for their cost too. You can shake/spin some of the dust out so that it doesn't get super-dirty, but I'm not sure how well this would extend the life of each disposable Swifter head...