Anyone else have an old Schmidt Black Magic hand sluice? I got one back in the late 90s and tried it out a few times. It has an undercurrent to create a fluid bed in the trap chamber, just like his Bazooka dredges worked. I liked it fine except that th4 grizzly tended to get full of pebbles too easily, and you needed a pretty fair current of water to get the fluid bed going well.
Looks like someone hasd bought the patent, and has come out with 3 sizes of them! The big one looks like it'd work a feller to death, the middle one is about the size of the old Black Magic, but it looks like he has modified the design somewhat.
http://www.bazookagoldtrap.com/products.html

BTW the fluid bed catches gemstones better than riffles any day... if you have them in your creek gravels....

-Z