actually this is a very good idea, i think i am going to give it a try as well......silica is being used to absorb moisture.....ie there was a small bag with silica balls in the box contained my hard disk when i bought it.....you do not have to rub the buds with silica sand.....i suppose all you have to do is, hang the buds upside down in a cool dark room with silica gel/sand/balls around and that substance will absorb the moisture coming of the buds.....in theory should work.....will definately give it a shot when the time comes...yet, i am still far away from harvesting my ladies