Do the Sniff Test. Simply sniff the Smelleze® pouches after a few days or a week to smell if they started to pick up the problem odors. If they have a slight smell it means that Smelleze® has started to work by absorbing and eliminating the odors. The longer they are used, the more odors they eliminate. So continue to use and reuse Smelleze® pouches as long as you need to completely eliminate all the odors.