Kelly, Would it work on a pack or would it compromise it's integrity? Answer do not use bleach. Bleach breaks down synthetic and natural fibers. A better option is to soak in something like "Odor Out" from a pet store. Rogene -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.5/110 - Release Date: 9/22/2005