That rack looks ineffective as shit, there is no ratchet so the torturers have to maintain tension by standing on the bars. Hope they don't slip and get a taste of the pain.
However there are quite some torture techniques that 'oh fuck, you better not make me cum' my would-be torturer shouldn't "call my bluff" on ... or should actually, idk.
But also - really? "You'd" would be correct?
Wouldn't that shift everything and so also required a "shouldn't have called" later on?
(And also was I, or both of us actually, not sure if they have already made me cum?)
Actually, there is. I had stretcher treatment for my back as a teenager, it was wonderful (especially combined with heat lamp and TENS treatment. Dangit, that's pure relaxation afterwards).