Room Shocker, which is advertised as an odour busting solution which uses chlorine dioxide fumes to penetrate through walls and remove any severe odor from various sources such as cigarette and cigar smoke, pet urine, vomit, soured milk, mold, mildew and bacteria etc. It will also decontaminate treated areas of harmful pathogens, spores and fungi that might also reside inside old walls (we hope this is not the case!). We'll ignore the fact the packaging makes it look like something we'd see offered at the local 7-11.
Chlorine dioxide was the same chemical compound used to eradicate dangerous mold from houses inundated by water after Hurricane Katrina and also has been given a USDA 3-D approval for washing fruits and vegetables to be used as ingredients of meat and poultry products. It is an oxidant like bleach, so keep away from cloth or carpet to prevent discoloration. At $25, it doesn't seem like a risky proposition to try, but maybe one of our readers already has experience with this product?
[Creative Commons Image: A.K. Photography]