I think that the multiple taunts only work in Duel or Power Duel. For me I would just continue to press taunt and eventually it plays one of the others.
I think OJP might have enabled the other taunts to work in all game types. I know it lets you use the flourish and gloat animations in gametypes other than Duel and Power Duel, so that might be worth checking out if you wanted to test your taunts in something other than a duel.
Hope that helps.