Perhap I'm being unfair to the device. Perhaps when it was new, all those years ago, it was actally able to do what its name implies. But now it doesn't. What it does do is extract swear words and blood in equal measures whilst scratching the paint on the pie tin a bit.
So next time I'm in a position to get one I'm going to get the finest and poshest opener that money can buy. Which is a gadget of sorts I suppose.