At the 2008 All-Star Fanfest in New York, there was a dealer selling capsules with sawdust from game-used bats from such players as Ty Cobb, Hank Aaron, and more. Here's a photo:
(Photo taken July 14, 2008. © Gary Dunaier. Link to upload on Flickr.com: here.)
The capsules supposedly contained actual sawdust from game-used bats used by the players noted. The dealer who was selling these said they came out a few years ago, and that he hadn't seen them around for sale that much and he was pretty much the only guy who was selling them. For all I know this was a big scam, but I bought a couple of Ty Cobbs ($15 apiece) anyway because they were produced by the Highland Mint, so I had no reason to question their authenticity.