A chain should be used.
I trained my horses to do showmanship with my own ideas at the age of 11 (me) and have kicked royal butt in the show arena, so no being nasty with the chain is not required and nor do I think it should be used.
I actually have to leave right now, but showmanship is my specialty. PM me or email me (email@example.com) and I'll tell you everything I know and my training ideas when I come home!
Tino's Nugget - 16.2hh Palomino Quarterhorse / Zip And Scotch - 15.2hh Palomino Quarterhorse
She's In A Tizzy - 16.3hh Dark Bay Thoroughbred / Dreaming Of Geneva -Grey 15.3hh Thoroughbred