I'm assuming that the detail wanted here is more for the party's benefit when they find the victim, as opposed to all the detail needed as to why the torture works, etc. so the emphasis is on visual impact, right?
So, something like:
"The door flies inward under the impact of your shoulder, revealing a small dark room, only lit by the flickering red light from a smoky, sputtering torch. The room is empty except for a dark shape in the corner, which upon closer examination appears to be a figure sitting in a chair. Or rather, bound to the chair by what appear to be rusty chains.
As you step closer, the acrid smell of burning flesh fills your nostrils, and underneath the guttering of the torch, you can hear a low moan coming from the figure.
Stepping closer, you see the broken figure of a once handsome man, chained to the chair - athough you doubt that in his condition he would be able to move at all.
Tatters of bloody skin hang in strips from the man's frame, his face a patchwork of exposed muscle and tissue. His broad chest is covered in deep open wounds, freshly made but mostly cleaned of blood - only small trickles of crimson mar his form. His arms and legs bear similar wounds - neatly cleaned but left open and exposed. It's as if he was sculpted and put on display..."
The horror being that the person doing this is convinced he is an artist - no need to "add" anything to his work. Let the players instead see through the eyes of the maniac, and see how twisted his viewpoint is.
that might hurt.
