A little field mouse decided to die in a part of our home with a crawl space. He conveniently died directly under a mounted furnace. Consequently the smell migrated to every portion of our home. Not only did this get rid of the remaining odor from our friend,., it also eliminated the disgusting chemical agents and fragrances from the other products we tried before we found these. I am highly sensitive to fragrances and searched for what were supposed to be "fragrance -free" products. They lie. Even the "sponges" which were supposed to be neutral were decidedly less smelly, but still time released chemicals into the air. In fact these chemicals have becoming more difficult for us to remove than the odor from decay. The chemicals attach themselves to everything.They seep inside of your cabinets and closets. I went for a trip only to discover my clothing had absorbed the chemicals. We've had these less than 24 hours and the bulk of the odor and chemical feel and smell is dissipating. The only place they seem to remain are in small closed areas like closet and laundry room. Buying a few more to hang in there to eliminate totally. and as back-ups for future outside visitors..