The pipe would make a nice sound too I imagine. What I am calling a 'bat' is the handle end and about two feet of a lunge whip that got broken.
The 4ft length is what I like. It's intimidating enough that if they're about to run over ya, they'll dodge off to the side, plus it gives you about the same reach as they have with their neck. By switching arms, you can reach either end of their body without moving too much so it helps with driving forward or turning back and they don't get as tore up about it as they do when you have a lunge whip.