Did you bury the package?haha.... I'm wondering if you have some pesky poltergeist or other paranormal creature in your house? I can't say I've ever found a wallet on the shampoo shelf.
I DID, however, start retracing my steps in the first few days it was missing. In those few days, I still kept thinking it would turn up so I wasn't freaking out about it. "Freaking out" still seems a little harsh term to use, but I definitely don't WANT to have to replace all those packets. When it didn't turn up, I started a more thorough and invasive search. Doing what you suggested....opening drawers, closets, cars, trunks, everything. double and triple checking areas I've already looked. Still no seeds.