The toad style is immensely strong and immune to nearly any weapon. When it's properly used, it's almost invincible.
11 seconds sound clip from the Five Deadly Venoms movie soundboard.
You can hear this line at 00:06:11 in the Blu-ray version of the movie.
Quote context
[...]
- After number three left, I took up pupils number four and five.
- Number four in fact was older than number two and three.
- The fifth pupil, he practiced the toad style.
- Four and five knew each other, but never met the other three.
- It can even bend solid metal.
- So then compared with the other pupils, you don't stand up, you're not really their match.
- I taught all I could, but time's run out.
[...]