err Guess you could convience them theres some nice new apartments in the otherside of town you should check out, but your new job prevents you from taking up this opputunity at this time.
Well you could be blunt and give them a date in which to be out or you could be nonchalant and genuinly ask how the job is going have they started looking for a place of their own, you know show a concerned side maybe that will entice them to move on.
But the cleaning part well that is only fair that you ask them nicely to do their share of the work.
Me personally if i was in that situation, i would do everything i could to get them out but in a non threatning manner.....and if they take it wrong well....thats there hangup and I go do what zanax suggested.
After all its your life, your happiness why should you be made to suffer while people take advantage of your hospitality.