How do I get Cliffy out of the brig?

Hint 1 of 7:

Well, make sure you can get to the brig first.  See the previous question if
you need help with that.

Hint 2 of 7:

You need something that will eat metal, but not eat Cliffy.

Hint 3 of 7:

Remember that the bars are made of metal.

Hint 4 of 7:

Do you remember anything else that could break through metal?