And here's another take on this: I never block socks. Here's why. . .
Yes, they do look more professional in the final product. But when worn, you can't tell the difference between blocked and not. Also, when you block, depending on the wool, the yarn may have permanant memory of the blocking. With socks, because they are such a snuggly fitting object, that may not be a good thing, and once you've blocked, you often can't change it back. And socks are usually hidden, or partially hidden, in your shoes or sandles or clogs. The only time I would block socks, is if they have a pattern such as cabling, which you want to make stand out.