If there is mold inside the walls, will the Homebiotic penetrate through the walls if I spray the outer sufaces? Ben Prasser Updated May 09, 2017 20:41 Follow No, it needs to have direct contact. Related articles What are the ingredients in the Homebiotic? What is the best way to kill mold before you spray on Homebiotic to prevent new mold from growing? I heard Charcoal can cause constipation? How is the blue light blocking filter different than the Night Shift mode in iOS, and do you recommend using both? Does Homebiotic remove mold odors and spores? Comments 0 comments Please sign in to leave a comment.