There are 2 very easy ways to kill every thing on/in them. The first is to toss them in the oven and heat them to 350F (double check this temp please). The other way is to soak it in a bleach/water soulution. Bleach kills every thing, i prefer the oven soulution myself just because its cheaper and less messy. You can find more info on the oven method all over the net, just look around.