Peleton is not and never will be 100% clean. That is impossible and not a realistic standard, no sport is 100% clean. What the sport can try to achieve is to have almost all riders clean and those doping to either be detected and punished quickly, or forced to hold their doping to a very low and thus less effective level, so that although an occasional result might be disrupted by a doper, there won't be dopers regularly making podiums at the expense of clean riders. The guy who won the Tour of Turkey, the two Vini Fantini dopers at the Giro - that sort of thing is going to keep happening, get used to it. There will be a 4 year ban now for serious doping cases, meaning that a rider probably won't be able to come back - I think that's pretty close to a lifetime ban except maybe for the youngest riders.