This effect was created by Arturo and was named L.I.N.K.S. for obvious reasons. The effect was extremely popular because performers would throw a bit of flash paper to "weld" the chain links together. As fire laws increased and more and more often tricks with fire became less and less popular, this effect lost some of its charm.
When putting this Halloween Special together I was reminded of one of the spookiest things I saw as a kid, and that was Marley's ghost in Scrooge (many consider Scrooge the first Sci Fi book ever written since it deals with time travel). Marley appeared as an apparition bound in chains and moaning and groaning. Perhaps a recreation of this on a smaller scale would work for Halloween shows and in particular, kids shows since it does have a message to it.
What you get when you purchase L.I.N.K.S. are 16 individual brass chain links which when dropped into a decorative canister, pour out as an 18" chain with all the links now forming this chain. The props are well made with the canister doing most of the work for you. However, things can go wrong with this effect if you are not careful, they are simple things but you should be aware of them.
When initially pouring out the individual chains there is a chance if you are not careful that some will roll or bounce of the table so care must be taken when doing this. It kind of breaks the atmosphere when you are crawling around on the floor looking for the brass links that just rolled off the table. You also need to get familiar with the handling of the prop, its not hard but if it is not handled properly the results could be very frightening.
The good news is the effect is easy to do, sets up quickly (as long as you don't drop any chain links on the floor), and can be performered surrounded. As mentioned above, a touch of fire or flash adds much to this effect so if that is possible by all means do it but like any fire or flash effect, please use proper caution). The first time you work the effect it you are almost guaranteed to have issued because of the unfamiliarity with the prop. It is easy to do, but you have to get familiar with the proper loading of the prop and the proper handling of the prop. After a few trial and errors its as easy as pouring sugar on breakfast cereal (without spilling any on the table).
Great story potential with this prop, I use a small skeleton from Walmarts as Marley. The effect is not cheap, but is under a $100 so its not a budget buster either.
If you have the type of personality that tell's spooky stories well, then this might be a worthy addition to your Halloween show.