Wool (especially unprocessed) is naturally antimicrobial -- you don't need to bleach them. (In fact, that would destroy a lot of wool's wonderful qualities. )
Just like a wool sweater, a soaker can be aired out between wearings, and be washed periodically. They work extremely well; I've used them for my children, too.
An excellent pattern can be found at www.woolywonder.com -- there is also a forum there for questions and pattern support. Wooly Wonder also has great patterns for wool shorts and pants, which can be used in place of soakers and in place of regular shorts/pants.