Can't use acid to progress in prison

[Lambchops]

Hi there folks.

I'm encountering what I believe is a bug in the prison section.

i've got a glass jar of acid which I presumed was to be used to weaken the lock on the metal gate to exit the prison area. however when I try to use it texts pops up on the screen saying "it would do no good."

i checked walkthroughs and it appears I am doing the right thing but the game is bugged.

Any suggestions for how to progress?

Cheers