I don't care if you think it's wise -- just build the device. I've lined your coffers with enough gold to feed half the Isles, and you never batted an eyelash before now. You've put in mechanisms that crush bones and sear flesh, why should this one be any different? The concept is as simple as it was when we first discussed it. Use a few of the standard statuary we've installed but modify the enchantment. A low-grade shock and some strong restoration should do the trick. There may be a few days between charges on an enchantment like that, but do you honestly think any more will be needed?