Where you find it depends on where your store stocks it - if they carry it.
It could be with the dishwashing liquids, among the oven cleaners, or mixed in with the things like Comet, Ajax, etc.
And, stores move things around without notice. The first time I saw the Reynold's Handi-Vac at Wal-Mart - they were in the cookware area - when I went back to buy one a few days later I couldn't find them. A couple of weeks later I ran across them by accident - on the other side of the store mixed in among the Glad food bags ...
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain