I would also add the following:
After cleaning as Dan and Ottawan suggest, allow the cuttings to dry thoroughly in open air (a few hours). When you return them to the bags for rooting, use newspaper rather than paper towels to wrap them (my experience has been less mold forms with newspaper). Do check them at least every other day (opening the bag allows fresh air to replace the stale air).
If mold starts to come back (it sometimes does), I have had the best luck using a "cornmeal" spray to get it under control. Cornmeal has natural anti-fungal properties. I make up a spray by soaking 1 cup of cornmeal (from the bakery section of the market) in a 1/2 gallon of water for 24 hours. Stir it up a few times during the soaking. Let all the cornmeal settle to the bottom and pour the clear, yellowish liquid into a spray bottle. Use this spray when mold first starts to re-appear. After a few treatments (usually over a couple of days) the mold finally goes away for good.
Note: if the cuttings are too far gone, the cornmeal spray will not work. If there is physical damage to the cuttings, you may not be able to overcome the mold issues.
Good Luck!