I occasionally indulge and purchase the Lavender Dryer Sachets from Trader Joe's. They're quite pricey in my opinion, around $4 for a plastic packet of four. I dislike the idea of tossing that plastic in the trash and the bags degrade so they're not infinitely reusable, despite the fact that the scent seems very long lasting. I've also had one pop open in the dryer and found my lint trap overrun with the contents. Luckily nothing overheated as a result of that incident.
Recently I found myself wondering what I could do to prolong the life of the two sachets I had in my laundry area and decided I would try emptying the contents into some fabric scraps and seeing how long the scent lasts. I can tell you that these two little sachets have been going for months now and still have a light, pleasant scent. I find the lighter scent more pleasing, I don't want heavily scented clothing, it will give me a headache, but I like having a dryer sheet substitute, since I'd never put one of those in with my laundry. Between my wonderful wool dryer balls and these sachets, we've got it all covered.