Anybody using that technique must have a hidden weak spot, and to find it, there's only one possible thing to be used. The iron maiden.
12 seconds sound clip from the Five Deadly Venoms movie soundboard.
You can hear this line at 00:54:27 in the Blu-ray version of the movie.
Quote context
[...]
- Keep them both in custody, sir, until Ho comes back.
- Be patient. You'll be alright when Ho gets back here. Don't fight, it looks bad.
- Now listen, he's one of the Poison Clan and uses the toad style.
- There, that's the thing. It has nearly 10,000 needles, and one of them has got to get the weak spot.
- Once the weak spot's punctured, the man's finished. His iron skin just simply stops functioning.
- But this torture, it's illegal.
- Not at all. He has to confess, we've got no choice.
[...]