The question isn't if the Dekko packs work. The question is are the silverfish eating into the pack. I don't have a big problem with silverfish, but when I see them I don't evidence that they are very interested in eating from the packs. I don't know if it is the location they are placed or something else.
Don't know for sure if these work or not. I have a silverfish infestation. I put the packs every where. Still seeing some silverfish but I guess it takes a while. I am hoping for the best!! The packets are self contained and clean to the touch!