I imagine they could use a belt sander to marvelous effect. Imagine if you had a large abrasive surface and slowly lowered the person onto it, feet first. Eventually, I guess you're abrade the person away to the waist.
After that, you could use razors to lightly fillet the skin on their arms. Hundreds of small cuts, each of which could have lemon or salt water applied.
A fork could be used to pluck out one eye and display it to the other.
Sleep deprivation the whole time, of course. With medication, you can keep anyone awake or conscious for quite a while.
Imagination can be a powerful thing. Especially when considering what to do with people who would take children hostage.