Why and How to Cleanse your Crystals and Gemstones - Pinny sez: I can't vouch for all of these, but some are good. Best is water bath, then sunlight to charge, or leave for a day or so on a citrine cluster (not amethyst). Burying in earth for a day or so is good, too.
Rutilated Quartz: Reduces coughing caused by bronchitis or asthma. It has a beneficial effect on the lungs, bronchial tubes and respiratory tract, combating inflammation. It promotes healthy sleep. If the wearer indulges in negative thoughts, it will help discover the truth. As a result, it makes possible for the wearer to bring about changes. It symbolizes truth. For thousands of years it has been valued as a protective and truth stone.