Freezing generally doesn't kill everything. It's not a reliable method for disinfection. We generally recommend using a 5% bleach solution (by volume). For pieces of real wood and that sort of thing, bake them in the oven for an hour or two should kill everything. I like to dunk real wood in very hot water for a while before baking it. There are plenty of threads on this topic on the forum. Scroll down to the bottom of this page and clink on the Similar Threads links.