Any movement or action will cancel a taunt once it becomes cancellable. You don’t need to dash (though you can), simple forward or backwards movement is enough.
Bear in mind that the crouching command taunt cannot be cancelled. But it has its own perks, being the only command normal in the game that can gain reversal properties and thus break armour.
(now I want to test if Dudley’s rose toss can also become a reversal, though it wouldn’t break armour even if it could because it’s a projectile)