With carb or O2 stones, pasteurize if you can, either instead of (preferrably) or in addition to chemical sanitization. The pores are too small for aqueous sanitizing agents to reach. I stick my O2 wand in the sparge water while it's heating up, for example. I would do the same for a carb stone if I used one.
>160oF for ~2 minutes all it takes. Pasteurization is always better than chemical sanitization, provided the equipment can handle the temp.