Pudz gets called a cokehead because he failed a WSM contest and it was not for steroids. I am not sure if it was ever released though what he failed for. Now that being said i don't think anyone really knows if he is cokehead or not. As far as drugs, all i can say is i have heard some stories from some decently reputable people and they are starting to dabble in EPO and things other than steroids. I am going to go out on a limb and say any sport that requires any strength and is not tested is going to be rampant with drugs.
As far as Poundstone, i don't like to accuse people of anything if they have never failed a test, because you really don't know. He posts at Irontrybe, you can ask him if you want.