Or you could link the two and just demonstrate a whip finish (i.e. nail knot) ;).
A well-tied knot of even moderate strength should hold securely against nearly any fish, and really should only break when you hang bottom, trees, rub against something abrasive, etc. The heavier stuff (like 6 pound or 2x and larger) should actually be difficult for you to break intentionally....if not, you need to learn and practice a new knot. Anything over 8-10 pound mono should require a gloved hand or wrapping the line around a stick to break off so you don't hurt yourself. Everyone knows that trick right? That's not just a Missouri paddlefish snagging trick I hope. 70-100 pound mono is fun; you get all kinds of treasures from the bottom.
BTW -- if you want a good demo aside from a beer tie thing, the local shops are staffed with good knotmen. I've said it before, but Rich Farino is one of the best I've seen.
Gene