I use vanilla quite a bit to make my Bourbon Vanilla Imperial Porter and I've never sanitized the beans, nor suffered any ill effects from not sanitizing them. By the time they get into the beer in secondary, the alcohol content and low pH of the beer make it pretty resistant to infection. And remember, the best part of the vanilla bean is the "gunk" inside it. Split the bean lengthwise, scrape out the "gunk", and add both it and the pod to the secondary. That's all you need to do. I dislike adding vodka to my beers since it adds a disagreeable "heat" to the beer.